I used tab groups all the time at work. Feature used to make me so much more productive, and its been missed since removed from Nightly.

Used to separate different workstreams into tab groups. Used to quickly jump between projects without the need to go hunting for the correct firefox icon. (had about 6 or so active groups at any one time).

Going into the tab group also gave a nice preview render of the pages within each group too - very useful for quickly picking out a tab that's miles away in the current tab group stack of tabs.

I really, really question the direction of firefox, and mozilla in general.

Had this about 2 years now, without fail...

2 * 9 gig Raid 1 SCSI OS drive
5 * 250 Maxtor Maxline II, in raid 5

Running Gentoo Linux, no hardware controller, all handled by the kernel. The rest of the machine is an AMD 500, 256megs ram. No X, nothing un-needed installed.

CPU usage never gets maxed out, and I can copy too, or read from at the max a 10/100 network will allow.

I'm very happy, as its got an uptime of about 200 days.