Advice needed on JavaScript control libraries

I'm looking for advice/opinions on Javascript control libraries like ext-js, dhtmlx, jquery-UI etc...

I've got some background in asp.net and hav开发者_运维知识库e found the various 3rd party controls to really boost development time.

I'm doing a project in PHP and have considered some PHP specific controls, however I suspect I would be better served long term by sticking to a straight up javascript control librarty such as those I've found with ext-js and dhtmlx. (I need a grid control)

I'm looking for opinions on this approach - am I on the right track, is there another library I should check out, are there some nice back end php scripts that make interacting with the javascript controls easier, experiences etc...

Thanks, - Jack

Bias note: I work for ExtJS.

ExtJS is great if you're building an application, you can really cut down your development time because the heavy lifting is done for you. Ext 3 has a new feature called Ext.Direct, which is used to ease calls between client and server. There's routers for a number of different server languages. You can find the routers here: http://www.extjs.com/forum/showthread.php?67992-Ext.Direct-Server-side-Stacks