I have a set, the only visible effect is the def. I'm hoping it gives a hidden effect of extra accuracy or something. Even if it doesn't, I still macro them for Last Resort and Sleep II...
Ahem. The AF boots are by no means crappy, and don't believe anyone who tells you they are. They are closer to unique.
The 5 mnd that you recieve from the boots isn't useless. Mnd is used in certain great sword weapon skills. The only one that comes to mind at the moment is cross reaper. Have em macro'd in there for a little extra damage and people will thank you for it.