there is a review on them on this site:
I have the MC one. It looks nice but i haven't used it in a game. I can acquire a sight pic no problem with my iron sights on my Kar98k and via the scope on my M14 with no problems whatsoever. if it doesn't work out, then its back to the Vforce grill. though i prefer the concept of the Save Phace cause a bb cant be shot through the mouth portion as on the vforce. the ear portion feels like im more exposed, but your ears ARE protected, so its probably just me worrying cause i was used to the grill.