I purchased a pair of Wolverine LTD 721's. I heard they ran large so I got a size 10 (I am normally an 11), they fit but thought I would go up to a 10.5. These fit perfect, like a glove. In fact these feel like I am wearing gloves, they are butter, so soft and smooth. I am wearing normal socks as I will wear these boots year round and can't see wearing even medium socks in the summer.
I highly recommend these boots, as far as sizing goes, a half size down works for me, but if I was going to be wearing heavier socks, I would probably gone with my normal boot size. My normal size of 11 would be too long for my foot, my toes are perfectly situated in the 10.5. The boots are a D and my feet are wide so that helps.