It runs small! I'm usually a 7,5 Medium and ordered an 8,5 after reading reviews. Glad I sized a full size up. It fits me perfectly with room to wear thin socks comfortably, or midweight wool socks snugly but still with comfort.
I find these extremely warm and comfortable. They kept my toes toasty warm through negative temps (as low as -20). But are breathable enough to allow me to wear them at warmer temps, when the weather was in the 30s and I needed waterproof shoes for all the melted snow puddles. I've worn them almost every day for the last two months and they are still looking awesome. I got the brown color and it's beautiful, even though it's chunky it has a cool Alpine-sporty-chic look. I just wish the soles were cream or beige and not black (the black makes it look more industrial).
I do find them a wee hard to put on and off compared to other lace-up snow boots I've had. I really have to loosen up the laces almost all the way down to put them on and off with ease--otherwise I'm struggling to pull them out!
The wool lining is of excellent quality, thick, warm, and well-attached (unlike other brands where the wool lining comes off easily in tufts).
This is a first-class warm, waterproof, functional winter boot that is also comfortable and stylish. Amazing purchase, worth the investment!