I think that the "Carbonium" topsheet also has some snow shedding properties that are pretty beneficial, especially when skinning. I remember hearing that from somebody.
I can't really say that it's better. It's certainly no worse than a standard fiber glass top sheet. It does resist chipping better. Though if you do get a cut in it, it will tear versus chip. Overall, I like it better than fiberglass, but as with anything it has it's quirks.