Paul is right. Also don't pay attention to the fact that the sig/san is a serious combat rifle fielded in many theaters, and that some of the advocates of that platform are professional shooters, whereas the XCR is not found in any conflict anywhere in the world, and the only people who recommend it are exclusively weekend shooters with no combat experience.
Also, definitely do not go look up what serious gun users on forums like Lightfighter or M4C have to say, or if you do, ignore their opinions. The XCR is totally on par with the SIG.