I have not used any other anti-snoring the device in the past, so based on my experience with the MRD-M2 I gave it 4/5 stars. My wife says it works to reduce /eliminate snoring so in that regard it gets 5/5 stars! The 4 stars because the online description says that "You can effortlessly reheat and refit M2 whenever you desire". The actual instructions that came with the device states you can only do so two times. I tried refitting a second time and I thought I had ruined the device since after boiling it the device was extremely flimsy and lost it's overall shape (maybe the water was too hot). I refitted it and the device is now a lot looser in my mouth. That is not a bad thing since it is now more comfortable to wear, though I am still not entirely happy with the fit. BUT, bottom line is that it is working for my intended purpose. I suggest that the manufacturer gives precise instructions indicating what temperature the water should be, not just stating “Boil a mug of water to a full boil using a microwave”.
After the first night wearing the device I had a lot of soreness in the teeth and jaw the next morning. I skipped a night then tried again. The second and third time using the device was very similar so that’s when I tried the refit. The fourth time wearing the device was better than the first three as the device fit looser in my mouth and the next morning there was much less soreness. Fortunately, according to my wife, I still did snore. Now I am going on about ten days of usage and still no snoring. I still find myself waking up during the night clenching my jaw at times, but I suppose that is a normal reaction to a foreign object in the mouth. I have very little soreness now and it is mainly located in the jaw, no longer the teeth.
I would purchase this device again.