Now, let me tell you how these fit. They fit perfectly with thin or even with thick socks. They are comfortable and I do not have heel slippage. One thing that is a problem is when I wear them without socks. They do have a bit of heel slippage. The Viberg slippers fit perfectly even without shoes when I first got them, but as I wear them more and more, the leather stretched. I did not think it would stretch out a lot like this. But it did for me. I did not try size Viberg 10 but if I could, I would. I will just endure the pain at the beginning for a bit and wait for the leather to stretch out. However, that of course depends on the material that it is built with. You know that Cordovan or horse leather does not stretch out or get loosen with wear. Also, I think leather is stretchier than other types of leather.