I would prefer a BC all moutain, for the simple fact that it's stiffer then the Seth, so less chatter, more edgegrip (for a park ski). It's simply a tank. Not as fun as the Seth for cruising around. One factor would be if you ski in crud alot (EC) or if you're in soft conditions (WC). More crud = BC. More soft, and possibly more park = Seth. The other factor is the weight. If your ratio weight/height is high, go with the BC. You can make the rest of the assumption.