The gaming I do isn't high-end modern gaming like Battlefield 3. Whenever I do any gaming I usually lower the graphics settings anyway (less distractions). The 6450 just barely passes the mark for what I want to do; something like the 7750 I mentioned would very probably end up being overkill in itself. I didn't buy a 6450 expecting a 6850
To turn back to one of the older posts about my comparison to Windows 7: I'm not a Windows user, but I needed Windows 7 over the last few months for work-related things. Windows' graphics are silky smooth, stable, don't tear, and generally performed faster than Linux with Fglrx. Obviously, I didn't want to stick with Windows for the sake of a more stable desktop. This is why I'll be grabbing some NVIDIA card. Granted, Fglrx has improved a lot for me over the last 6 months, but not really worth messing with any more.
Edit for more stuff:
My setup is new-ish, and not *that* great. Good enough aside from the 6450, though:
Phenom II x6 @ 2.9 ghz
8 GB DDR3 memory
Crappy generic 250w PSU (replacing that)
AMD 785G chipset