Keep in mind, I really like the fox, but on my 4 year old machine (Win XP, 2.8 GHz, ~700MB RAM) it’s like a torture looking at the task manager seeing Firefox using 95% of my CPU and about 200MB of RAM. It’s almost impossible to use any other program while browsing with Firefox. I couldn’t stand it anymore.
CU Firefox, bye bye Thunderbird… Hello Opera!
I easily managed to import all my local bookmarks via Opera’s importer, the only thing I couldn’t get solved was importing one out of 4 email accounts I’m using (maybe because of several subfolders?) and the (logical but) annoying fact, that I can’t import my passwords from Firefox.
BTW: The time I was typing this, Opera used between 2% and 12% of CPU and 95MB of RAM.
Edit: If you encounter similar problems but you are a Mozilla Evangelist and/or you prefer opensource, use Mozilla Seamonkey instead of Firefox and Thunderbird.