I'm just beginning to see how interesting this new version of FF is. But I've found some really nifty new addons that take advantage of some stuff and/or make what I used to do (save offline to read) MUCH easier.
See this article on lifehacker and just follow the links all over. *G* Currently I'm waiting to try
Read It Later. And while del.icio.us complete is not ready for FF3 yet, the less complex but still useful official del.icio.us addon is updated, so I can live for now.
The things I'm seriously noticing are: Much smaller footprint. Everything is zoomy! And I tend to go between HUGE amounts of tabs and very little. So far on 2 windows and 85 tabs there are NO PROBLEMS. FF2 used to choke pretty easily on that. (Shut up, I hear you judging me.) Gmail seems to confound it from time to time. No big deal really, but if you leave it up all the time like I do, sometimes the 'server is busy' and nothing but a refresh will fix that. The ctrl + for fonds seems to have been fine tuned. I.E. there are more sizes in general. I find I have to hit it like 6 times for the too big size on LJ rather than 3. Which is great, because in reality the old choices went between too small and too large.
So, what are YOUR new favorite bits of functionality and extensions?