I've never had any problems with Firefox, even with using 6 or seven ad ons. But I also don't open very many tabs/windows at a time. I've seen some people who complain about memory leakage whose problems didn't occur till they were opening 30 or 40 tabs at a time. (I don't know how they'd keep track of that much stuff at once or why.)
Nonetheless, it was an interesting article, well worth checking out.
