I have never used a gum shield before and was very aware whilst grappling about knocking my teeth which can't have been a good thing because I would prefer to concentrate on task at hand. I have a session tonight so will be able to test drive my new shield out
I don't do hardcore sparring at all. It's mainly grappling working towards the sub but occasionally we mix it up with striking (on the ground) to help improve positions and to add some pressure/urgency.
I used the shield and have to say it was better than I thought it would be. One boil and bite session is all it took.
Conclusion: happy with my purchase.