Re: Nvidia cards are fine
The problem with proprietary drivers for Nvidia or ATI hardware is that they both silently remove support from older chip sets.
On two occasions with Ubuntu, one Nvidia, one ATI, I've put some updates on a system (one was a dist-update, and the other was just a normal in release set of updates), rebooted, and been faced with either a text login screen, or a 640x480 16 colour screen.
In both cases, the support for the graphics card that was in the system had been removed from the proprietary drivers, so the system defaulted to the highest system it could use. This is far from ideal, especially when Linux is seen as suitable for older hardware.
Nowadays, I recommend that users switch to the Open Source drivers before doing any major updates, and as I don't have any major reason to use heavy 3d applications, I use them all the time.