I have been using a Mantis-X training device as part of my dry fire practice for a while now. Recently I bought a magazine adapter to fit my non-railed guns. I am posting this because I do believe the device can be helpful if you know what it does and you can determine that what it does is what you need. The Mantis is primarily an accelerometer, used in combination with tracking and analysis software. It quantifies success by measuring how much, or how little, you move the gun when pulling the trigger. It has a bunch of built-in diagnostics that are intended to help the user diagnose *why* they are moving the gun. I’m ambivalent about these. In the beginning they may be helpful, but at a certain point they’re just not. Either you’re moving the gun or you’re not and, if you’re watching the front sight, you can see where it’s going and diagnose it yourself. In any case, once you reach a certain profeciency level the “diagnostics” often conflict with each other and make little sense. In my opinion what remains useful and helpful over the long term is the measurement of how much (or how little) you’re moving the gun, the variety of circumstances and drills in which you can practice not moving the gun, and the continuing measurement and tracking of your progress against the objective standard of not moving the gun at all during trigger press. Yesterday, for the first time, I achieved near-perfect single-shot scores. I also had significantly better times while achieving thise scores. Here are examples from the begining and end of approximately 1 month of regular dry fire Mantis training. This is October 22, 2018. This is a reaction time drill - pull the trigger at the buzzer. Movement scores are not bad, but look at the times. Now here’s yesterday. In this drill I got my first near-perfect (zero movement) score of 99.9 and I also did it in .17 seconds. This is a considerable improvement, but it is not worth much if it doesn’t translate into real world results. So here is what else happened during this month. I have a weekly training class on Sunday afternoons from Noon to 6pm. It’s a comprehensive class incorporating marksmanship fundamentals, defensive training, and gaming. Runs every week with 10-12 students (It’s the same group of students, more or less, each week so the whole group progresses at about the same rate.) Due to my travel I often miss one, two or more classes a month. From Oct. 22 to Nov 26 I missed three of five classes. But after missing three straight weeks - during which I worked a lot on dry fire with the Mantis - I went back to class and had lost nothing on the other students. In every area in which dry fire training can help, I had made at least as much progress as any other student and had improved basic multi-shot accuracy more than the others. There are a lot of other things about the Mantis that I like and can go into more if others are interested. It is not everything you need, nor is it the only thing you need but I do find it to be a helpful aid that produces real-world improvement for me. Having said that, if you can pick up your handgun and routinely put five shots into a 2” circle at 20 yds then you aren’t moving the gun much at all and may not benefit much from what the Mantis does. You may still find the drills enjoyable, or some other aspect of the online training capabilities, but it’s likely to be more a maintenance tool for you and/or you might not like it at all. This is simply my experience (no financial affiliation whatsoever of any type or kind) with the device after about a year of on-again/off-again usage and finally figuring out how to take best advantage of it for my specific needs. Use at your own risk. Your mileage may vary. I will continue to use it because I see quantifiable, verifiable improvement in my performance and I’m happy to answer questions about it (to the extent I can) from anyone who is interested.