The difference is pretty incredible. For the first time, I can actually run Source Engine games at medium/high detail.
TF2 actually looks pretty nice, for a change (compared to what it used to look like). Overall, the jump in performance is about what you would expect.
Unfortunately, none of this has fixed my PC problems. I'm still getting plenty of Blue Screens of Death and I'm honestly near the end of my rope. Somebody pointed it out to me, but I've replaced almost the entire system chasing down various problems and it just seems to be getting worse. I'm actually expecting to get a BSOD any second now.
The only options still left to me regarding what to replace is to buy a new motherboard, or buy a new HDD. It was bad enough when I'd have old hardware and this would happen, but now I have all this nice new stuff but it feels like I can't use it because these BSOD error codes point to what sound like very serious problems in which the solutions are very vague and extremely varied.
It's just... argh. Every little bit of extra money I've gotten in recent months has gone in to trying to figure out what is going on in this PC. Spending $30-$40 every 3 or 4 months is getting old.
Though I will say, these PC problems have given me a boot in the arse to buy new PC stuff. If it wasn't for those, half the upgrades I've bought already probably wouldn't have been a reality and I would've just bought DS games or something. So that's something to be happy about, right?