The ECS is passively cooled, and is not available locally. It may not be important, but that cooler alone is worth $25. Able to keep the 9600GT within reasonable temperatures with minimal airflow and zero noise. I'm getting two of them myself for SLI gaming, to be put in a nice cabby with some fans. Hopefully they won't run as hot as my current card.
I was running some old games at 1680x using my GTS 640, I suspect that for maximum performance with new games at that resolution you'd actually need a GTS 512 or at least a well-overclocked G92GT. Oblivion ran smooth enough but had a few slowdowns in battle scenes with my card, I doubt the GTS320 would perform at all, and a single 9600GT whereas a little better than my card, would not provide absolute smooth gameplay either.
My installed Oblivion uses a very large texture mod, various visual mods, all eye candy enabled and HDR + AA simultaneously so it's quite a system killer. The GTS 640 would give average 25fps, with peaks of 60fps indoor and 45-50 outdoor. Got very choppy in battle though.
