Dude I'm currently trying to decide between those two exact same boards also (with 2-3 cm less).
These Kessler seem absolutely amazing but the price is just so high it's almost ridiculous. And from what I have read, they do not last for very long. Most people seem to keep it for one or two seasons at most. I've also read that some even managed to break them in two, which kinda sucks when you buy a board this expensive. I'm guessing they're great if you have sponsors to back you up, but other than that it's like buying a Ferrari.
So, right now I'm heading more towards a Prior Metal. They also seem like killer boards, all the reviews I have read are really good, and the price is more decent.
By the way, is there an expert around who could tell me what bindings fit well on a Prior Metal? I've been looking at the Catek OS2s, they look really cool. What else should I consider?