Laptops, man, laptops. Even ATI's desktop graphics are kinda suck, but at least they can be worked around and you can download new drivers from ATI's site. Laptop chipsets, you can't get anything from ATI for. The "drivers still suck" part? Crashes, instability, and poor planning. nVidia's control panel doesn't require .NET, and neither should ATI's. ATI's control panel intrusively adds itself to all context menus, takes forever to load, and is a pain in the rear to use (I tried showing my Business teacher how to use it to turn on the projector on her new class computer, and I think she blew a fuse).
My current issue with ATI is unstable default drivers provided with Windows 7 for my X1200 integrated GPU. ATI denies the existence of both Windows 7 and this GPU, even though the laptop is only about 6 months old. Can't go into hibernate because it always crashes coming out, and about 1 in 10 times I resume from standby, the display doesn't come up and causes a BSOD about 20 seconds later. Win7 64-bit is just an unusable nightmare for many of the same issues, only greatly magnified. I've even had it crash while Windows was running - and I don't even do any gaming on here!
The .NET thing is merely an issue with execution. Their setup program is botched. It detects that you don't have .NET Framework installed (as is typical when setting up a new computer), but instead of offering you the option to install it later due to that error, it plows through the installation anyway, and leaves you with a totally screwed up installation that takes hours to untangle and correct, even after installing .NET Framework - it then gives you cryptic error messages on each startup about a missing assembly (something like MOM.Implementation) until you uninstall the whole driver, delete the ATI folder, then reinstall the drivers and control panel. All because it decided to install despite the error. Yeah!
nVidia, for me, just works. I don't do a lot of high end graphics, I just want a card that works well, and nVidia has always given me that. I've had an opportunity to play with an X260 card, and I quickly found out about that poor thermal management problem. It would stick at 30% until it's about to melt metal, then finally kick the fan up higher. They seem to have fixed that issue in later revisions of the card. The software doesn't control the fan speed; the card's BIOS actually controls that. There are mod tools to download the BIOS, modify the parameters, then reflash it, to keep it cooler. But yeah, that's not a great solution, and they should have done better. But at least they don't make huge mistakes all across the board like ATI seems to do!