[ScottWhigham]

Hmmm - looking back, I'm not sure why I'm on 3.0x. Were there new features? JSON backups - whoopee! Other than that, from a user's perspective, I'm not sure there is anything better. 2.x was fine by me too.

[pbhj]

I quite like the awesome bar now (was that in 2.0?); some CSS3 support too. Bookmarking tagging, update checking are good as well. Improved SVG support I use occassionally for viewing.

Other than that I suppose faster javascript and optimisations through use of sqlite for history/bookmarks is good.

Probably a few other things if I thought about it.

Main features are in add-ons for me, firebug, yslow, noscript, adblock, seoquake,download toolbar, greasemonkey.

I keep a separate clean profile, without all the footer-bar ("clutter bar") icons for the wife to use whilst surfing

[stepherm]

The "awesome bar" (updated address bar) was added in 3.0 I believe.

[FooBarWidget]

* Awesomebar. Some people hate it but I love it, and in Firefox 3.5 it's extremely easy to disable via the GUI.

* Bookmarks. I can easily bookmark any page by clicking on the star next to the address bar. Clicking it again allows me to edit it or remove it. I use this all the time.

* History with search.

* Spell check. I used to think it's useless but now I cannot live without it.

[robin_reala]

Because the number of users on Fx2.0 is low enough that we don’t support it any more. It won’t look broken for the most part, but there’s no guarentees as we don’t actively test in it.

[thaumaturgy]

2.x has at least one rendering bug that was fixed in 3.x -- whatever rendering bug it was that I discovered the other day but can't now recall.

[mr_justin]

Because the JavaScript engine in 3.0 is lightning fast compared to the 2.x engine and the 3.5 is ummm, faster than lightning. By a heck of a lot.

For me personally, the only reason I downgraded back to 3.0 from 3.5 is because Firebug 1.4 is bloody awful at the moment (in beta). Other than that, Firefox 3.5 is great.