There is an old guy at my mountain that swears by them.  He is an X racer, and just carves down runs on them, with no poles.  He has good form, and you can tell he is a good skier, he just likes them for some reason.  I will never hate on him, or someone else that are shredding on them like that.
That being said, snowlerblades are a joke.  Everyone I know, even snowboarders get great laughs even seeing someone on those things.  They are the ultimate gayper utensil.
Other interesting fact:  The first handrail ever published was of snowlerblades.
But yeah, don't use them unless its gayper day or you really really want to.