Hey DJ,

I started with the stock brake-disc hexes, but found on the uni's I was using (the shorter broadtech / eagle ones) that the wheels would eventually fall off (wasn't enough thread coming through the lock nut).
I switched to some broadtech / eagle TT01 brake disc ones which seemed to be just a fraction thinner.
With my alloy rear knuckles there was some binding so I then switched to some TT02B hexes which seem to be working well.

Personally I don't like clamping hexes but that's only because I stripped a screw in one a while back.

Cheers,
Crouch