I saw the DRX at a model fair last year, and was impressed by the size and quality..
BUT!!... It doesn't have a 2-speed. So basically, the other two cars will be TWICE as fast. I got the DM-1, and it is fun.. Mine's been pretty high maintenance though, and a much bigger investment than I wanted.
The DRX is so damn cheap over here, I'd just say, if you like it, get it... Needs a 2-speed though IMHO...
The DRX is more a drifter I think. The IGT2 is much more capable, but needs a few mods from what I hear. It's also discontinued I think. The DM-1 is not all that easy to get parts for IMO.. At least compared to my offroaders..
Much better RC than all of the above??.. Associated SC8....