I like the idea of those but a rail mounted system doesn't seem like the best way to train. I have a friend who uses the G Sight Elms system and he loves it. It significantly increased his time to target. He just sets it up around his office and that's how he takes breaks. Since that's an inside the barrel laser, it feels more realistic to where you are pointing. That kit is something I'm considering as well. Nice way to save money on ammo and still train whenever you feel like it.