I bought them from DC4 and Daniel recommended to size the same as my Red Wing moc toes. So mine are US10 as are the Red Wings I have and they fit really well. I remember them being quite easy to get on but at first getting them off was a little workout. But after some wear it has gotten a lot easier and I wouldn't say it is too difficult. I think that they are shaped so that there a bit more space than some on other engineers (again, no prior experience with engineers) for the mid foot and ankle so I think that helps with getting them on and off.