Sierra Designs Drizone Primaloft Packable Bootie SKU #7332760(View on Zappos.com Classic)

Warm - Pros: -Warm synthetic (cruelty free) down fill; add a thick pair of socks and the effect is doubled. These would be great for wearing inside of a sleeping bag, but I use them for a drafty apartment. -Slip on like socks and stay on reasonably well; I'm a size 11. I bought the XL (11.5-13)since my toes felt cramped in the L (10-11). My feet do slip around on the inside when moving quickly, but the ankles don't sag. -Rugged design; I expect these to last a long time. All of the materials are high strength, stitched to the hilt, and tear proof. The soles are made from a stiff fabric and I could conceive of heavy outdoor use tearing these up, but then, you should be wearing shoes instead if that were the case. -Lightweight; Ok, I don't backpack or care about material packing weights, but these are light and they scrunch up easily enough if need be. -Synthetic material; of the down filled booties I tried, some were warmer, but almost all of them had feather ends piercing the fabric which made them scratchy, stabby, and uncomfortable. This is not a problem with these synthetic filled booties. -Low key design; the design aesthetics, including the logo, are minimalistic. My gripe with most footwear is the lack of simple design. These are simple. Cons: -I would have liked more insulation. As warm as they are, a 700 fill equivalent would have been nice. -Inside stitching; The stitches connecting the sole to the rest of the booty form a stiff ridge around the foot and this can be uncomfortable. -No sliding; The materials grip stays while my foot leaves. -They swoosh. It's the material. If I lost these, I would probably look around for something with similar characteristics, the main difference being warmth and comfort in the 5 star range. These booties are solidly a 4 star for the price, fit, function, and design.