For most skiers and snowboarders, 10,000mm is the sweet spot. This rating means the glove's membrane can withstand the pressure of a 10-meter column of water before leaking—which translates to solid protection in powder, wet snow, and typical storm conditions at the resort or in the backcountry.
The real advantage of 10,000mm is balance. You get reliable waterproofing for the vast majority of days on the mountain without sacrificing breathability. Higher ratings like 20,000mm+ offer more extreme protection but can trap more moisture inside, leaving your hands clammy during high-output touring or warm spring sessions.
Stick with 10,000mm if you're an all-mountain rider who sees varied conditions but doesn't regularly deal with coastal rain events, deep wet powder, or multi-day guiding in sustained storms. It's more than enough for standard resort days, powder mornings, and most backcountry tours.