ORM for PHP - performance problem

What do you think, should I use ORM like Propel or Doctrine? For a new PHP Project. Are there any performa开发者_运维问答nce issues?

When you start a new project you can get Objects in and out of the database fast, without worrying how you do it. You can also switch DBMS very fast from SQLite on your local dev machine, to MySQL on your testing or staging servers. When the performance part kicks in, your application has already matured a bit, models are somewhat fixed and programlogic is running. Extending the models to use SQL instead of the ORM is more convenient then, because the structure of the project isn't changing (so fast) anymore.

I suggest doctrine.