I use the PMS50  with the C-130 ans it makes handling the navigation controls on the radio frequencies so much easier.

Your speed calculations are off as they dont match the pms 50.  They are slower.  Its not the pms 50 as i found with other aircraft that they match, but they dont match on the c-130.

I have the H variant, why havent you included a digital cockpit and FMS  on the J variant ?
otherwise they all appear to be much the same, with minor differences and you expect people to pay money for the same thing.  Glad i didnt upgrade from the H version.