Comment Try a modern game (Score 1) 160
That it runs TF2 well isn't saying much. That wasn't very intense when it came out and it is very old. TF2 runs great on integrated Intel cards. Try a game that is a heavier hitter, and uses more modern API calls. Then you'll see issues.
Se what you are really saying is "A problem can be fixed by throwing enough hardware at it." Your GPU and CPU are unimaginably powerful compared to what was available in 2007. So of course it runs well, it could be running at 25% efficiency and still run well because your monitor's scan rate is the limiting factor.
However that's not so easy to do with new games that push the envelope. You can't just throw tons of hardware at them because they are already pushing the high end hardware that is out. So efficiency matters. If the driver is slow, you are going to have poor performance.
Further there is the issue of crashing. AMD drivers seem to have a tendency to 'asplode when you start throwing some of the new features at them. These features are there for a reason, they allow greater detail, more efficient rendering, new visuals, etc. If you can't support them, then that's an issue.
If you want a real test, fire up Metro Last Light Redux, see how that works.