Jay,
I agree with what you are saying. And my only worry is the "stock" T-56 won't hold up. Strength is the only advantage of the TKO. (IMHO)
D&D makes a T-56 that is converted from a Viper T-56 and can handle 650#T, but cost is $3k (or $1k more then the stock). It is reworked with better cones, keys, shafts, syncros, and a 26 spline. Comes from Chrysler not Tremec (some legal thing with who owns the tooling).
Hopefully the stock T-56 will survive or a least long enough so I can recover from the initial $$$, without any fixing or replacing
Rob