This thread comes up every so often, and I almost always give the same answer. So not wanting to break tradition, here you go.
The only benefits of mounting forward of center is enhanced switch riding and arguably easier tail grabbing. However of course by mounting forward of center, when you want to ride normally you're disadvantaged. The only time I would ever reccomend mounting forward of center is if your on a symmetrical ski, spending 100% of your skiing time in the park, and of that, 50% of the time, you'll be riding/landing switch.