Overall, I'm really impressed with Gore Bike Wear cycling products, and these booties do not disappoint. Over the past 10-15 years, I've never found cold weather cycling enjoyable because no matter what I tried my feet got cold on longer rides (anything over 90 minutes). Not any more! These booties are really warm, and you can even wear thin socks underneath. So far, I've been on rides into the upper 30's with toasty toes (with the thermo lined model). The booties go on relatively easily, but it can be a snug fit if you have shoes with a wide toe box (e.g. northwaves), but maybe that's a good thing to help keep the elements at bay.