@linuxrocks2000 when it comes to performance, I feel that it comes down to whether the browser supports hardware acceleration and if the pages you're browsing have a lot of ads.
So on Linux, chrome/chromium hardware acceleration isn't always a given. Or at least it wasn't, I haven't checked if things have changed but before you would have to build Chromium with hardware acceleration enabled.
As to the ads, the browser would require to have an ad blocker automatically built in.
But yeah, I've been pretty busy with work. I haven't checked out Firefox GX, but those Firefox-gx guys should add my suggestions if they haven't already.