I bought a Klein when Lee Valley stopped carrying my absolute favorite:
http://www.leevalley.com/us/wood/pag...11,43417,53912
The description doesn't mention that each end of the shaft is a different size nut driver. The ball detents on the bits work extremely well.
They haven't sold it in a while, but it is still listed on their site for some reason. Maybe if we bug them enough, they'll bring it back.