Funny you should ask. I picked up an XCR a couple of weeks ago. I'm working through the reliability part of my testing now. I have 1,300 rds. through it, the last 900 of which have been without cleaning or oil. I've put several different types of ammunition through it and other than an occasional adjustment to the gas system, it seems to be running very well.
The ergonomics are better than the AR and is does seem to shoot a little softer, but I think that is more a result of having the weight of the gas system out over the barrel. I haven't done any real accuracy testing yet, that will come after the reliability test, but I have no problem making head shots on steel IPSC targets at 200 yards.
The worst part of the rifle is definitely the trigger. Simply put....it sucks. There are things you can do to make it better and I've done a homemade trigger job and got the trigger down to about 4-5 lbs. Prior to that it was up around 8+lbs. Robinson Arms just announced that they have a "match" trigger that will be available shortly. The claim 3-4lbs., so we'll see how that turns out.
All in all, I've been very happy with the XCR. It handles well and the controls are very intuitive to use. Providing the new "match" trigger lives up to it's expectations, the XCR could give my POF piston-driven rifle some real competition as my primary instructing/training rifle.
USSA-1