When I first started using this mouthguard I hated it. It felt so big in my mouth that it was hard to breathe and I would occasionally gag. I threw it off to the side of the court because I felt that it was doing more harm than good.
Then a few weeks later, I chipped my tooth. Luckily it was just a slight chip, but it got me to make a trip to the dentist for a customized mouthguard. Since I've been waiting for the mouthguard to come, I've been using the shockdoctor again. Now that I am used to it, I am no longer bothered/having trouble breathing/gagging all the time. I've come to realize that it actually offers a lot of protection, and the gel feels pretty nice on the teeth.
I am regretting going to the dentist to get a mouthguard, because this one definitely does the trick for about 1/20 of the cost.