Eclipse Version differences

I currently use Eclipse Helios, and I need GWT Designer and GXT for my project. I also comfortably uses Aptana for Ruby which is also installed on Helios perfectly.

The database I need to use for my new project however would be IBM DB2, and I need to install IBM Data Studio, which seems to be not compatible with Helios. I tried to put Helios folder on IBM installer to let IBM Data studio install, but the installer said that I need some required minimum version. I noticed that IBM Data Studio uses Ganymede as its base.

So my questions are, if I revert back to Ganymede, what feature would I lose? Are all my tools run on Ganymede? Or better yet, can someone point me on how to update the package and install IBM data studio on Helios?

These are the requirement list for IBM Data Studio.

Some features and bundles of your existing Eclipse installation need to be upgraded with newer versions or are missing.  You must update your existing Eclipse using its Install/Update manager.  Use its "Help -> Software Updates -> Find and Install..." menu item to invoke its Install/Update manager.   Alternatively, you can download the features and bundles from eclipse.org.
  Feature "org.eclipse.datatools.connectivity.oda.designer.feature_1.8.1.v20100618-4107w3121151A1A53" needs to be updated to version "1.9.0.v200902280844-7C7iEQ7CYQCD_CZQ0Gsbd"
  Feature "org.eclipse.datatools.connectivity.oda.feature_1.8.1.v20100618-7H7C7ACcNBHBBkHeGSMd" needs to be updated to version "1.9.0.v200902280844-7F7iEC3BcMAB0APMvAsYW"
  Feature "org.eclipse.datatools.enablement.apache.derby.feature_1.8.1.v20100618-77778eBmKDNOMgJvJ8Of7QBR" needs to be updated to version "1.9.0.v200902280844-67q-AlRMQHHa6mIdwQGCK8DDI"
  Feature "org.eclipse.datatools.enablement.ibm.feature_1.8.1.v20100618-7F47SFC7sRbrSZope9vW" needs to be updated to version "1.9.0.v200902280844-7D8u0EB7sQSMRCr6ZcGW"
  Feature "org.eclipse.datatools.enablement.jdbc.feature_1.8.1.v20100618-4-29oB56N5N7L6PAQ" 开发者_JAVA百科needs to be updated to version "1.9.0.v200902280844-37BEQ79oA55V5FBJ7CCH"
  Feature "org.eclipse.datatools.enablement.oracle.feature_1.8.1.v20100618-548cAkF79P7UBMATEE" needs to be updated to version "1.9.0.v200902280844-47U0_kE77g7MBZAWKQ"
  Feature "org.eclipse.datatools.modelbase.feature_1.8.1.v20100618-77078CcNBGKBZI_FcRd" needs to be updated to version "1.9.0.v200902280844-67cEQ7BcMAB0AXKSEROS"
  Feature "org.eclipse.datatools.sqldevtools.data.feature_1.8.1.v20100618-640BgJ9DI9ZHVDdHL" needs to be updated to version "1.9.0.v200902280844-37P-9oA55V5I8F_DFH"
  Feature "org.eclipse.datatools.sqldevtools.ddl.feature_1.8.1.v20100618-277078B03G8S_IMz00IwOmQz00Vl" needs to be updated to version "1.9.0.v200902280844-27G-84B_tQF8HjTNKHDbOxHz00dZ"
  Feature "org.eclipse.datatools.sqldevtools.ddlgen.feature_1.8.1.v20100618-7A-2F7RZHLz-HvNlPz-Uk" needs to be updated to version "1.9.0.v200902280844-777qEC3CYQCDACaNwGz-cY"
  Feature "org.eclipse.datatools.sqldevtools.feature_1.8.1.v20100618-7N7y7AFDrhoZFIFUNhpFwckfaS-S" needs to be updated to version "1.9.0.v200902280844-7F9A-E8zTnlz-F0sj8WVDp1sU_lK"
  Feature "org.eclipse.datatools.sqldevtools.parsers.feature_1.8.1.v20100618-622BgJ9CR9XFcEWLP" needs to be updated to version "1.9.0.v200902280844-57QEC3AgI99q9SHQ_MFN"
  Feature "org.eclipse.datatools.sqldevtools.results.feature_1.8.1.v20100618-4209oB57E5N8H9ICE" needs to be updated to version "1.9.0.v200902280844-37HEC39oA55V5GAS6OCG"
  Feature "org.eclipse.datatools.sqldevtools.sqlbuilder.feature_1.8.1.v20100618-79-3EVVFJoFsJcMz0Pe" needs to be updated to version "1.9.0.v200902280844-67q-BcMAB0AQJlBrZQ"
  Bundle "org.eclipse.datatools.connectivity.apache.derby_1.0.100.v200906020900" needs to be updated to version "1.9.0.v200905272100"
  Bundle "org.eclipse.datatools.connectivity.apache.derby.dbdefinition_1.0.2.v200906161815" needs to be updated to version "1.9.0.v200904110060"
  Bundle "org.eclipse.datatools.connectivity.apache.derby.ui_1.0.3.v201007080903" needs to be updated to version "1.9.0.v200903231723"
  Bundle "org.eclipse.datatools.connectivity.db.generic_1.0.1.v200908130547" needs to be updated to version "1.0.900.v200905272045"
  Bundle "org.eclipse.datatools.connectivity.db.generic.ui_1.0.1.v201004070709" needs to be updated to version "1.4.900.v200904300004"
  Bundle "org.eclipse.datatools.connectivity.dbdefinition.genericJDBC_1.0.1.v200906161815" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda_3.3.1.v201008030730" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.consumer_3.2.3.v201005281018" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.design_3.3.1.v201008171206" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.design.ui_3.2.4.v201007150318" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.flatfile_3.1.1.v201001131420" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.flatfile.ui_3.1.1.v201001131420" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.profile_3.2.4.v201007150318" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.oda.template.ui_3.2.1.v201004090942" needs to be updated to version "3.9.0.v200902280844"
  Bundle "org.eclipse.datatools.connectivity.sqm.core_1.2.1.v201008120113" needs to be updated to version "1.4.900.v200905282304"
  Bundle "org.eclipse.datatools.connectivity.ui.dse_1.1.4.v201004270430" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.iseries_1.0.2.v201005211230" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.iseries.dbdefinition_1.0.3.v200906161800" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.iseries.ui_1.0.1.v201005211230" needs to be updated to version "1.9.0.v200905291747"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.luw_1.0.2.v201005211230" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.luw.dbdefinition_1.0.4.v201005211215" needs to be updated to version "1.9.0.v200905271128"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.luw.ui_1.0.2.v201005211230" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.zseries_1.0.2.v201005211230" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.zseries.dbdefinition_1.0.4.v201005211230" needs to be updated to version "1.9.0.v200905271128"
  Bundle "org.eclipse.datatools.enablement.ibm.db2.zseries.ui_1.0.1.v201005211230" needs to be updated to version "1.9.0.v200905291747"
  Bundle "org.eclipse.datatools.enablement.ibm.informix_1.0.1.v201005211230" needs to be updated to version "1.9.0.v200905271859"
  Bundle "org.eclipse.datatools.enablement.ibm.informix.dbdefinition_1.0.4.v201005211230" needs to be updated to version "1.9.0.v200905291333"
  Bundle "org.eclipse.datatools.enablement.ibm.informix.ui_1.0.2.v201005211230" needs to be updated to version "1.9.0.v200905060052"
  Bundle "org.eclipse.datatools.enablement.oracle_1.0.0.v200908130544" needs to be updated to version "1.9.0.v200905271929"
  Bundle "org.eclipse.datatools.enablement.oracle.dbdefinition_1.0.101.v201004211630" needs to be updated to version "1.9.0.v200905071834"
  Bundle "org.eclipse.datatools.enablement.oracle.ui_1.0.2.v201005051303" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.modelbase.dbdefinition_1.0.2.v201002130228" needs to be updated to version "1.4.900.v200904300004"
  Bundle "org.eclipse.datatools.modelbase.derby_1.0.0.v201002161452" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.modelbase.sql_1.0.4.v201002250945" needs to be updated to version "1.0.900.v200905142330"
  Bundle "org.eclipse.datatools.modelbase.sql.edit_1.0.1.v201002161452" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.modelbase.sql.query_1.1.1.v201008100700" needs to be updated to version "1.9.0.v200905202345"
  Bundle "org.eclipse.datatools.modelbase.sql.query.edit_1.0.0.v200906022249" needs to be updated to version "1.9.0.v200903030235"
  Bundle "org.eclipse.datatools.modelbase.sql.xml.query_1.0.1.v201004291415" needs to be updated to version "1.9.0.v200904230100"
  Bundle "org.eclipse.datatools.sqltools.common.ui_1.0.0.v200906022302" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.data.core_1.2.0.v201005241300" needs to be updated to version "1.9.0.v200906022030"
  Bundle "org.eclipse.datatools.sqltools.data.ui_1.2.0.v201005250945" needs to be updated to version "1.9.0.v200903312339"
  Bundle "org.eclipse.datatools.sqltools.db.derby_1.0.0.v200906020900" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.db.generic_1.0.0.v200906020900" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.ddlgen.ui_1.0.1.v201002270530" needs to be updated to version "1.9.0.v200906051811"
  Bundle "org.eclipse.datatools.sqltools.debugger.core_1.0.1.v201005250945" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.editor.core_1.0.0.v201001150815" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.parsers.sql_1.0.2.v201004291415" needs to be updated to version "1.9.0.v200904250115"
  Bundle "org.eclipse.datatools.sqltools.parsers.sql.lexer_1.0.1.v200906030654" needs to be updated to version "1.9.0.v200904250115"
  Bundle "org.eclipse.datatools.sqltools.parsers.sql.xml.query_1.0.0.v200906022302" needs to be updated to version "1.9.0.v200905220200"
  Bundle "org.eclipse.datatools.sqltools.plan_1.0.0.v200906022302" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.result_1.1.0.v201005260930" needs to be updated to version "1.9.0.v200905291806"
  Bundle "org.eclipse.datatools.sqltools.routineeditor_1.0.0.v201003161000" needs to be updated to version "1.9.0.v200902280844"
  Bundle "org.eclipse.datatools.sqltools.sqlbuilder_1.0.3.v201009131745" needs to be updated to version "1.9.0.v200903030240"
  Bundle "org.eclipse.datatools.sqltools.sqleditor_1.0.1.v201005130745" needs to be updated to version "1.9.0.v200905121950"
  Bundle "org.eclipse.datatools.sqltools.sqlscrapbook_1.0.1.v201005250945" needs to be updated to version "1.9.0.v200904272237"
  Bundle "org.eclipse.datatools.sqltools.tabledataeditor_1.0.1.v201005250945" needs to be updated to version "1.9.0.v200905081654"

Thank you

As far as tool compatibility you need to check each tool you are concerned with individually.

Concerning this...

So my question is, if I revert back to Ganymede, what feature would I lose?

...I find this site helpful for collecting the "new and noteworthy" for each release. This link in particular has the Helios laid out, but also has a link to what's new in Galileo.