I haven't actually played a game with one, but having held the newest toy to hit the scenes, my only useful comment is about the "space grip" wierd curvy gripframe thing.
Although it's a nice idea, once you slap a drop forward on, the drop forward sticks out of the back of the curve.
Although that was a pants explanation, hopefully he following will help:
gripframe /
__/
------¬
dropforward
leaving you unable to put your hand right on the bottom of the curve. Of coure, I'm sure it will take no time at all for specific drop forwards to come out (or it could be that the one I held was set up wonky?).
I know it's only a little thing, and a pretty useless review of the IR3, but spending that much on a marker, I want to be able to hold it comfortably.
Odds on in a couple of days this thread will be filled with rave reviews.......