hmmmm, do you still have that TR Legend install, if so, do me a fav. Download and install the 81.98 drivers, and play the game at 1280x1024 with shadows off, water reflections off, reflections on, next generation effects on, no AA and tell me how your performance.
Maybe its different on XP, but using windows 2000 which i am using, whenever i use the 6200, the BFG version, i use 81.98 and the performance triples.
In the GPU-Z this is what is suppose to say for correct stats.
Bandwidth = 4.3
Core at 300
300
Memory at 266
266.
I haven't played with the 6200 since my computer is bottleneck free now(when i do, the performance should have triple in games). But from past experience using XP, i notice there is a slight bottleneck when the bandwidth increases to 8.5, from 4.3. I haven't tested out alot of games, and half of the games will not work good as for performance when the bandwidth is at 8.5. One example, this game called the thing:
It will be choppy as hell with 8.5, depending on what driver you are using, because i did notice using the 175.80 at 8.5 bandwidth the game work just fine, but using say the 177.92 it didn't perform as good, but still going back to the older 81.98 the thing game, work beautiful.
Keep in mind, don't know if this will work on your rig, because your computer is pretty great IMO, but i would try out the older drivers, the 81.98 , they seem to work better then the new ones.
Anyways, if you do decide to buy the 2400HD card, when playing Tomb Raider games, in the sound area, always turn hardware sound acceleration off. Because if you don't there is static in the background it kinda slows down a bit.
Even tho my 6200 runs the game slightly better, it doesn't slow down as much when looking at everything in front of you. Seems like the 6200 can render everything faster or something.
But the 2400HD can run it pretty good at 1280x1024, with Fullscreen Effects on, next generation effects on, water reflections off, reflections on, i get about 19-55fps.