Merino wool insulation is a great choice if you run hot on the mountain or spend a lot of time touring and working up a sweat. Unlike synthetic or down, wool excels at managing moisture — it pulls sweat away from your skin and releases it, so your hands stay dry instead of getting clammy and cold. It's also naturally odor-resistant, which is a nice bonus on multi-day trips.
The trade-off is that wool doesn't pack as much warmth per gram as synthetic fills like PrimaLoft or down. So for bitter cold or low-output resort days sitting on the lift, you might find wool underpowered unless it's blended with another insulation. Think of it as your go-to for moderate temperatures, high-output days, or spring touring when breathability matters more than maximum warmth.
Wool also appeals to riders who prefer natural materials and want something that still insulates reasonably well even when damp — just not quite as effectively as synthetic does when truly wet.