i really depends on the ski-if the ski is made to be centered, it will ski easier cnetered than one designed not to. chekc threads specific to your ski.
for ym scratches i found them waaaaaaaay easier to set and edge and carve forward non-centered, but carving is lame anyways.
as for pow, the tip-bindign length is smaller, but who fucking cares, if you have your weight centered when you ski pow, whihc you should, you'll be fine