Proximity to the server (low ping) is probably about as important. There are other troubling issues with the streaming approach. You are wholly reliant on the service at all times. If a game becomes inordinately popular, demand may exceed capacity. (I'm not sure how the game-running tech works. The obvious approach is a separate game instance running for each user, but I suppose a system which saves and restores virtual-machine states on the fly might be employed to get a single instance to serve multiple users. This would add to lag, unless the system is so godly powerful that it doesn't much matter.) And games may get yanked from the service at any time, much like Netflix lost some of their content not long ago. Also, the service may go belly up, leaving you completely in the dark. That happened within the last few years with the first such service (I think), whose name I now can't recall. I know of one guy who was playing Borderlands through it.
The up side is being to play any game on any platform capable of streaming. That's nothing to sneeze at, but it simply isn't for me. I need to have my games running right here, under my full control. Old dog, new tricks, and all that.
