Snap and buckle closures are a great choice if you're looking at over-pants hip protectors—designs that strap on outside your ski pants rather than underneath like underwear. They're especially popular with racers and skiers who want to quickly put on or remove their hip protection between runs without stripping down.
The biggest advantage is security combined with convenience. Snaps and buckles keep pads firmly in place during aggressive skiing, and they offer quick release when you need to take them off fast. That said, they can feel bulkier than pull-on compression shorts, and the hardware might create pressure points under tight ski pants.
If you ski with loose-fitting outer layers or race gear, or if you want the flexibility to add and remove protection without changing your base layers, snap/buckle closures are worth considering. For most resort skiers wearing protectors under their pants, pull-on compression shorts still offer the most streamlined and stable fit.