schmies pretty much covered it as far as differences between the two. one thing to add though, if you're on the west coast, you're probably better off with the PE since it is a little wider and will be inherently better in softer snow. if you're stuck on the east like me, the silencer might be a better option. its a little bit lighter than the PE and the narrow waist will make it quicker edge to edge on our firm snow. i've skied invaders for a season before i got on k2s and my skiing improved drastically when i got on a real ski. the invaders are fun for jibs, but the k2s can actually ski outside the park, and take a beating much better than my invaders did. hope that helps.
and frodo has a sick van.