I only found out few days ago but those 2-3 extensions allowing non compatible installations are not really needed. Look for extensions.checkCompatibility
in about:config set it to false. May be what you meant. If extension maker have not updated yet or show no activity look for alternative.
Well, I doubt you have a more "dirty" Firefox than mine and it never use 200mb unless there is media involved. Be careful with numbers, look for reasons if "high memory usage" alarm goes off. 6-7 tabs of Eyeball pics and you are up to may be 350mb - minimize oops down to 1x mb. How it goes, takes 1 second at most. Not like Firefox has stolen memory for good. If you only close tabs, compare Firefox with Opera/IE7 and you see big difference. Goes for all pages I think, still not stealing but it does not want to let go easy and always takes a long time. So level is high because of crap code or because it is aggressive by nature when using memory? Both? For example default setup will not page out memory by minimizing (speed is top priority not low memory usage), opposite most other software.
I also use a lighter Firefox edition on a computer 1/4 as powerful as this one. Dont think Ive ever seen 100+mb, more like 50-60mb with a handful of tabs. Those numbers say nothing other than you have to know conditions in details. That Lifehacker "test" and most complaints shows the same. Only interesting is extensions and pages visited. Numbers alone dont say much. I dont know if you expect 10mb or something but lets say 50-75mb on a 512mb then? I find that reasonable and only notice because I monitor it. If I can run Firefox for as long as I please with no slowdowns or lockups then I dont think a (other browser)79mb vs (Firefox)102mb is something to cry about - should that be the case. I dont use Firefox because it use less memory than the other 2. Sure developers get lazy if no complaints and sure they are not done with optimization. Take a look at Bugzilla. Im not saying Opera does not use less memory in general but that you cant make direct comparisons from what is seen at a certain moment - which is what most do. Im also saying I dont buy the diesel tractor image some paint, heh - or that 200+mb is something you have to live with. There will be reasons or Mozilla close shop tomorrow. FF by itself is a hog? That is an oppinion about what is too much again but still does not change the fact most complaints in this area can be explained and fixed. As with MSN tab browsing or the old Adblock for Firefox it only take 1 bad add-on to change situation.
The way things goes there was never a chance to get a 100% perfect 2.0 much the same way as 1.5.x.x would never be perfect. They move on when they consider code stable. Just the way it is. Would be nice with a cleanup/maintaince/tuning 2.1 version with zero new gadgets but you wont get it. Ive seen that suggested even on Mozillazine. For each X version they should make 1 cleanup version. But, you think that would solve your problems? May be 3.0 will be less "who cares" about reclaiming used memory. They already lowered cache defaults in 2.0. Easy trick, but 1.5.x.x defaults were also quite high.
A clean Firefox on a not sluggish computer takes forever? You have timed it? Well ok, annoying if you have to restart over and over. If that annoying you will stop doing that
or use other browser. I imagine this could drive some crazy and others will shake head, Im in last category but also have Firefox open for hours and hours, can even be days - cant break it
I have same relation to XP bootup time. Im not completely satisfied with Firefox either but cant have it all. If it was strangely unstable as some dev. builds have been I would scream but memory usage bahhh, under control
I know exactly how an unstable Firefox feels, often connected with high cpu/memory usage. Unacceptable of course. Solve problem or get rid of it.
Btw, are you restarting Firefox for a particular reason? Cant stand to look at high numbers? Use Auto Reset Browser Extension http://extensions.he.../Auto+Reset+Browser/
For the very interested, heh. Works on 2.0 and does what it says.
Much Firefox/Opera on a thread about IE7!