Fit like a glove!
These gloves are perfect for when you want something lightweight (but warm) under your bulkier mittens. I have small hands (sz 5-6, Women's)and the XS in Men's fit perfectly on my hands and under my mittens. They are very soft and fit so perfectly that you can easily manipulate zippers, buttons, etc without taking them off, which is a real perk when it is freezing outside!

Great Liners - Warm and Light
These are great glove liners. They are warm and light, and offer excellent dexterity. I use them alone when photographing in chilly conditions. I combine them with fingerless mittens in cold weather, and with Outdoor Research Gore Tex mittens - with chemical heaters - when it's REALLY cold. I am very pleased with these liiners.

Running liner
These are excellent gloves for training running, when temps drop down to ~35F. They are thin, yet provide excellent amount of insulation when you are doing active sports. I've also used them under snowboard gloves, and they provide good amount of warmth while being comfortable due to their non-bulky-ness. I have a small hole developed under my left palm, and Ibex has provided a replacement without charge. So definitely, you need to be a bit careful with them. But the holes don't affect function and they haven't gotten bigger yet. Overall, highly recommended if you expect your gear to get reasonable amount of wear and tear on them.

Perfect Liner for Winter Sports
I wore these on a recent snowboarding trip to Heavenly in Tahoe, CA. The first day temps were between 25 and 40 degrees, the second day high of 20, and the third day was nearly 60. So we got a little bit of everything for weather. The first day they were all I needed with an outershell for water protection. The second day I did need fleece gloves between the liners and shell and the third day I was down to just the outershell. Overall these liners were great - exactly what I wanted and expected. They kept my hands dry and warm for snowboarding. Since I am from SC I expected cold hands on the very cold day.

These liners are awesome. They are warm, fit very well and are very comfortable under mittens. Although I have not had them long enough yet to determine durability, they seem to be very well made and should last a long time.