These slippers are super warm and comfortable - I got them for my sister as a gift and she loves them. They're definitely true to size, but size up if you are in between sizes normally.
I love these. I usually wear the loafer style because I don't like my heel slipping around, but these work for me. I read dozens and dozens of reviews saying to "size down." I followed that and had to return them. I am a normal 7.5 in shoes. I usually get a size 8 in UGGS when they only have full sizes. Based on reviews I got a size 7 and regretted it. They didn't fit right and my heel was too close to the back edge of the slipper. Returned for the 8 and they are perfect!