I recently had the experience of doing the same thing (a search combo box) with jquery and extjs. I found extjs to be buggy and overly complex. On the contrary, I found jquery to work very well and be very simple. I am wondering what are other people's experiences of using extjs. Does extjs complexity actually buy you something?
They are not comparable imho.
jQuery UI is just a combination of a couple of widgets which can be used together but are not really integrated or anything. Quite extensible, quite fast, but not a complete widget toolkit.
ExtJS is a full-blown widget toolkit Web App framework that is comparable to most GUI toolkits in terms of features. yes it's useful, but it's also very complex and very large/slow. So imho it depends on what you need. For a normal frontend I would never use ExtJS since it's way too large and slow.
But for an Admin panel or something large where it actually adds a lot of usability, yes please.
Just try and create something like this with jQuery UI: http://dev.sencha.com/deploy/dev/examples/grid/totals.html
Also, with ExtJS you can even design your interfaces with a drag and drop interface these days: http://www.sencha.com/products/designer/download.php
Size comparison:
jQuery:
jquery-1.4.2.min.js
: 70.5KiBjquery-ui-1.8.5.min.js
: 199.5KiB- Total: 270KiB
Ext:
ext-all.js
: 697.7KiBext-base.js
is 26.5KiB- Total: 724.2KiB