Well it's not quite that you cannot game on a Quardo, more like you cannot use the "advanced" gaming gimmicks. Honestly, I wouldn't be missing the functionality of streaming to an nVidia shield.
(I wouldn't consider buying one in the first place, to be honest. xD I'm quite alright with my trusty XBox360 controller.)
(By the way I don't know if anyone offered this solution, but the reason GeForce doesn't do surround on Linux is not that they don't think much of Linux. It's quite the opposite. They consider Linux a "professional" platform, ie. the people who want surround on Linux are architects, engineers, etc. working at some design lab running CAD/CAM, and they should buy the more expensive "professional" card.)
Anyway, I was wondering what a Tesla card can do, ie. what do you gain from modding your GeForce to a Tesla, as opposed to a Quadro?