I agree with you. I've been using Ubuntu 8.10 and now 9.04 lately on my notebook (Thinkpad T61, 1.8ghz C2D, 4gb ram, Intel 965 gfx), I upgraded to the 9.04 repo sources in the hopes the crappy Intel xorg drivers would be fixed, but alas.
I find Firefox, with some flash, scrolling or resizing just completely slows my machine down, with XP and Vista this was much faster. I also tried Opera, which uses the QT engine IIRC, faster, but still irritating.
Other things that just annoy me about Gnome are the panels, there seems to be no way to do basic things like keeping the bars under windows, they seem to only exist in 'always on top' mode unless autohide is enabled, which I don't want. Even switching to a lower resolution will result in my applets randomly relocating themselves, even if the lower res is more than the length of my panel + applets.
I want to use Linux on my Thinkpad, I am starting to seriously love Gnome now, but the hardware / performance of Xorg just plain suck for me.