I'd go with that line of thought too, and add that in general you'll
have an easier time getting gpl to work on an nVidia card, but if an Ati
card is working well it'll be as good or better value for money.
It's a very similar situation with intel vs AMD CPUs. Each have their
strengths & weaknesses, and each have their die-hard fans, but the
performance of virtually any new hardware will be enough to run gpl
acceptably, and if you get something mid-top spec you'll be able to run
at some very high resolutions & filtering levels.
As a result when choosing your hardware gpl's requirements aren't really
all that important, it'll run okay on whatever you choose. Pick the
graphics card that only has bundled games you are actually interested
in, and don't base your buying decision on features you'll never use in
the life of the card.
Malc.