ExtJs - your opinions
 

I stumbled upon ExtJS and seems interesting.
I've been using Prototype/jQuery for few of my projects, but extjs seems more advanced.

Your opinions on this matter.

Snook had said in his livechat that ExtJS is a powerful library for Air applications.

I've been pondering whether to use jQuery or not... prototype and mootools both seem ehh..

ExtJS seems quite interesting though, i'm in limbo between that and jQuery

Depends on what type of features you need.

I use jQuery or Mootools for frontpage dev and ExtJS for the backend. Since switching to ExtJS, my backends only use PHP for data interchange and storage and auth/session handling.