Hi all. In the process of updating my mod, I revisited the Oblivion units conversion question. After running some numbers and doing some research, I am more convinced than ever that the fMagicUnitsPerFoot value of 22 is a more accurate number than the 21.33 that is presented on the Oblivion units page. My reasoning is included on the discussion for that page. I'd be curious to hear other folks' thoughts on the subject.
http://cs.elderscrolls.com/index.php?title=Oblivion_Units

I've never had to be that precise with the units. Since the 3DS Max units match the game units, I don't need to worry about it. In game, it's usually good enough for my purposes just to set an arbitrary distance when testing how close something is.