It certainly is convenient! I like mine so far. I have the very basic model. I don't think it's ever missed a shot and based on Brian Litz's test I believe it to be accurate. It does shift on the barrel a bit so you have to check it after each shot. That is on a thin Kimber Montana barrel. I don't know about group size and POI shift for sure. I plan to actually shoot groups one after the other to see what happens with and without. My initial impression is that POI has not shifted much if any. The sensor is very light.
