This is a big one for me! I love how the streaming works and how smooth it is, but I primarily game with a controller on my remote machines. My Surface Pro 2 is either on a table in front of me, or is connected to the TV. In either case it's much much easier to navigate with my controller than to try to tap the little icons on the screen (or get up and do it in some cases). I've had to setup a network mouse on my phone to get around this for the moment. A real UI for the controller would be much better.