dstiles - 7:17 pm on Jul 3, 2013 (gmt 0)
Currently 5 FF windows open here (linux Mint Maya) with a total of about 60 tabs spread between them and 14 add-ons and 6 plug-ins. I often have more windows and tabs. Never a crash and no user problems apart from a minor exception of tabmixplus preferences colouring.
I use FF for almost every browsing action with a very occasional use of Midori and Opera when testing a few weird things. NEVER Chrome!
And using linux, of course, no MSIE; almost true: I have an online windows server that requires MSIE to update it and I tried to download a file with it yesterday - it was tied down so tight I gave up. :)
3Gbytes memory on a 6-core AMD processor.