In my opinion the race works really don't gain you much more protection over the original. Plastic is pretty tough. The key to protection is dispersing impact and gliding over objects versus getting caught. The chaincase protector has a rather squared off leading edge. Rotor side isn't as bad but could be improved. I'm working on something to supplement existing guards that will disperse impact and allow glide action up over object.
For simple clarification think of a ski. If leading edge of ski is formed at a 90 degree angle do you think it will glide over a log? The protectors on chaincase and rotor need to function the same as a ski.