1. Being a web developer, I need to use Firebug, web developer toolbars and some other essential extensions. These do not work with FF3.
2. My theme foxdie safari blue too does not work with it.
wow...just now got ff3 downloaded and installed...when started for first time most of my existing addons gets updated automatically except aardvark and gmail2. Anyway nightly tester tools comes into rescue to install them as well.
I dont see any performance difference, both seems to use same memory but ui has got some improvement with the default skin being completely revamped.