It’s effectively the same thing in a transport Aircraft, but it’s reliant in all cases on the validity of the data input.
I use a good rule of thumb that works most times as a gross error check. Ultimately in Mil or Civ service we operate for the most part by numbers, but you can’t replace experience and the seat of the pants either.
BTW, my old bang seat Jet was underpowered with both engines in reheat!