IMO, they all are very close to the same in power. The beta 4.2. I think was the start of the R tunes. The TNTR's were the first " R " tunes. Then Revo came out with all it's adjustability which turned the R tunes into 5.x versions
Again, IMO, all these version have their own little issues. It's the reason for the continued development. Everyone who doesn't have a R tune I'm sure will get one from Bob when either your truck is ready or the latest refined version is available.
I can't speak for Bob though but, this is what I assume to be the case.