[iRFNA]

Well, it appears to double the distance they can move in battle, but no effect on map move. Although it's tough to come up with a reason to use those boots instead of birch boots (if you have the token 2 construction), one use I found for them is getting flanking thugs behind enemy lines faster when I had no option for flight. Assuming the thugs are with an army, of course. That actually was quite useful in some limited circumstances.