Yes there are plenty of arguements, I agree that bang for the buck is definately important, but drivers, support, cooling, rate-of-failure are also important and should definately be considered by many. If you don't want to OC or don't care that a single slot is noisy or want to replace it, then by all means save some cash and get the cheapest model you can.
I am happy with the GTX's cooler, it's not very noisy, yet it's very effective at keeping mine cooled, whether OC'd, stock speeds, vmodded, etc. Fan speed is two clicks away and has been from the start. The drivers have performed very well with great stability in VISTA x64 of all OS's. I say go with what suits your needs and wants. There should be no ATI is better or NV is better here, just what should fit the shoes of what's needed by the individual. I've purchased from both sides for varying reasons, and for no reason did I second guess my GTX260 purchase in this current generation of released GPU's, both sides have great releases if you want to get realistic about it, both are more powerful than ever. What it comes down to beyond the pissing and moaning and techno talk is what flat out works and what doesn't for ya. Make your damn decision, enjoy it and get over it! Or keep waiting for that next, next, next best thing in 3-6 months!