I have one and love it. The Teamspeak app is a must have now that I've used it. Also, Red Orchestra has great integration. I can play the game without any HUD whatsoever getting in the way of the game. It doesn't sound like much, but it's one of those small things that goes a long way.
That said, I don't think that it would be at all practical to show a full replacement for an RTS hud in the G15 display, but something like what Dark_Axel said is a great giant leap in the right direction (if you can 'hide' it on your monitor while running it on the G15, that is)