Mantis X fan here. I like the various drills it offers, as well as quantifying my performance. It tracks gun movement before, during, and after the shot, and and creates a graphic trace that you can literally play back. No, it doesn't give you a dot on a target, but I don't care, I'm more concerned with trigger control. If the Mantis says I scored the same or nearly the same on 5 consecutive shots, it means those 5 bullets all went the same place. If those aren't bullseyes on live fire, it simply means my sights, or my sight picture, need adjusting. Plus, it's a proven system for me, my shooting definitely improves when I'm using the Mantis regularly, and goes downhill when I'm not, a problem exacerbated by my inability to get to the range on a regular basis. Later.
Dave