I friend of mine has a 2003 F-250 with the 7.3L Diesel for sale that I am going to look at tomorrow. It has 75,000 miles on it, and I know it has had meticulous care (he is a retired heavy diesel mech...
Well, maybe I am crazy but I have had two 4R100's well past 130k and they were nearly perfect. A lot of them were replaced due to some shifting problems that may be able to be traced back to the valve body. Pretty easy fix.
Keep it cool, keep the fluid changed and don't join the HP war and the 4r100 is a pretty decent 4 speed transmission.
Add power...and yep.. you have decreased it's service life. That is NOT the fault of the transmission.