I found beta 4 to be the sweet spot of FF 3.0 for me, as I didn't care for B5 or the RC1 releases. There were just too many incompatable add-ons at that time.
I haven't d/l'd RC2 yet, thinking that the add-on developers will need some more time.
For sure though, FF3 is a better performer than FF2 (which I have used for years).
thx...