My dogs and I are new to disc. I'm still trying to get my dogs super motivated about the game. The best part about the Hero Sonic 215 for me is they are durable enough that i can let my dogs tug with them as a reward for fetching all the way back to me. This warps the disc, but does not affect the safety, there are still no sharp edges to injure their gums. I can't toss this disc as far as some of Hero's others, but I find myself using these the most often. (Posted on 11/18/09)