i have small hands so the XS was wonderful. they kept my hands VERY warm during a spring ski trip to west virginia. not bulky, but lots of warmth

Marmot makes great fitting gloves and these are no exception. Not as warm as midweight fleece gloves but i love the water resistance and all leather palm/finger for grip and durability. I like them for backpacking/hiking in wet conditions in the 35-45 deg range, plus or minus depending on the individual and exertion levels. I personally have cold hands and could never use them for even warm weather skiing.
One issue i have is the cuff (more of a nitpick). It is a little bulky and stiff which makes it less ideal for cycling. Also, it doesn't provide the best seal for warmth, but the cuff design is still satisfactory. Overall, i'm glad i bought them for the applications stated above.

As a ski instructor, I used these gloves any day it was over 40 degrees. They worked great for sure. They kept my hands nice and toasty but breathed fairly well. Unlike most bulky gloves, I could really maneuver my hands well and do things like use zipper pockets, write stuff with a sharpie and help people with equipment problems, all essential tasks for a ski instructor.