So I just reviewed the Nvidia Shield... but maybe I didn't answer every burning question you might have. Here's your chance: I'll be tackling your questions right here in this forum post.
I've used the Shield for a whole month now, and have been playing with PC streaming for about a week. If there's anything I can't answer right away, I'll try to test it, or ask my Nvidia contacts about it.
Let's do this thing!