Alright. None of these posts are very accurate.
I have the SPK PRO's and love them because
1. I have never had shin/toe bang in them and jump Freeway @ Breck.
2. They are stiff enough to take out of the park into the trees/ big mountain.
The leather isn't what makes them more stiff though, dude's retarded^. The leather is simply slapped on over the plastic.
The Kreation's aren't as stiff and also don't have as good of "bang" protection. The leather is a negative of the pro, because yes it rips easy, but as of next year they will no longer be made with leather.
Bottom line:
If you're a park rat that doesn't have an issue with shin/toe bang, get the Kreation's.
If you like to go huge or take your riding to big mountain, get the Pros.
They pack out A LOT so make sure to get a size smaller than your usual size. (That's why people start to get shin bang with the SPK'S.)