PhysX and CUDA .... unless you are a developer and unless the games specifically utilize it there is no discernable difference - in fact I would argue that it is unnecessary features that bloat the price but does nothing for the average consumer.
Tessellation .... the new AMD cards have it.... Linux support? Seriously though this is just nitpicking at best; proprietory AMD drivers are very good.
Why don't we talk about Windows drivers by NVIDIA compared to AMD then? I am sorry but AMD/ATi proved they are moving with the times as opposed to NVIDIA who still parade their ugly Nvidia Control Panel interface as if it were 2006. And yes LOOKS do matter.