Water beads up and rolls right off a hard shell, while soft shells absorb moisture like a sponge - that's the core difference, and it matters more than people realize on Colorado snow because the stuff there swings between wet slush and dry powder in the same day. Hard shells have a rigid outer layer (usually plastic-y feeling) that actively repels water, while soft shells are stretchy fabric with water resistance that works fine in light conditions but breaks down when you're getting hammered or spending hours in wet snow. Since you're doing day trips and mixing terrain, a hard shell is probably your move - that waterproofing becomes the real workhorse when you're off-piste and hitting unpredictable snow that's been tracked out or warmed by the sun.
Here's the practical hack though: try the jacket on with your base layers and arm position at the ski shop before buying. Hard shells can feel restrictive at first, and if you're a naturally tense skier you'll hate it even more. The stiffness some people complain about? That usually settles once you're actually moving, but if it drives you crazy when standing still, you'll resent it all day. Also grab something with pit zips if you can - they let you dump heat without fully unzipping, and on a Colorado spring day when the sun's cranking that's worth its weight in gold.
One more thing: check the seams. A hard shell is only as good as its seams, and cheaper models have taped seams that degrade over a season or two. Mid-range jackets usually have solid construction that'll last you several seasons, which is why spending a little extra on hard shells makes sense - they hold up to the punishment better than soft shells do anyway.