The new firefox 3.6 alpha has blown 3.5 out of the water and it has been surprisingly stable for me...
I got 30% score increase on the peacemaker benchmark score..
I guess we have to thank the chromium team for pushing Mozilla to move its ass so we can <3 firefox more

give nomoroka a try but remember it's still a minefield! :P
I have been running minefield along side the regular Firefox for a year or so.

Pretty fast and responsive.