If you've got a midfat ski and plan to ski literally everywhere on the mountain in every condition possible (as you mentioned), these are the bindings for you. I have a pair of Griffon Schizos on my 2010 K2 Kung Fujas and they work like a dream. They're a great binding if you want to have a one-ski quiver.
They will mount to any ski, but K2 factory skis come with pre-drilled "Schizofrantic Inserts". These are basically just threaded holes inserted into the ski that make it easy enough to mount the bindings yourself. However, if you choose not to use these holes, the beauty is that the structural integrity of the ski is not compromised.
The durability is practically spoken for: Schizos are designed off the same reputable Royal Family toe and heel pieces. Mine have held up just fine to skiing all over the mountain and landing hard switch in the park. If you're going to be taking massive switch hits and 450ing onto rails in the park, I would recommend a fixed-mount binding (like the regular Jester or Griffon).
The only thing you have to be careful of is sliding the binding too far forward or back. This is easily avoided by the clear markings on the platform (stop, -3, -2, -1, 0, 1, 2, 3, stop). Also, if you anticipate that you will grow and your boot size will increase, you can adjust the binding accordingly, but you compromise the full 6cm of back-and-forth movement. If you don't want that to happen, basically the only option is to remount so you can still get that full 6cm range of adjustment.
Another minor setback is the weight. They feel a lot heavier than conventional bindings, but I have gotten used to it (plus I also ride Hellbents with Dukes - how's that for heavy?!). It shouldn't be too big a deal, really. If you plan to do some sidecountry stuff at all, I would recommend putting them on a pack. It helps distribute the weight better and is just all around more comfortable than tiring out one shoulder. I love my pack for carrying my Kung Fujas and Hellbents. But I digress...
Bottom line:
If you're looking to achieve a one-ski quiver, 49% of your choice lies in the ski and 51% lies in the binding. Get the Marker Griffon Schizo and make the most of it. Its convenience, durability and ease of use will not disappoint. I was a little skeptical too before I bought mine, but I'm a firm believer now.
