Dingo, you started this thread with the best of intentions,
and that's admirable.
However...
Technically, Chessrock, et al, are correct.
Once the signal is compromised, it can never be the same as if
a high end pre was used from the start.
Some top level pro's, like Mixermann, will run things like multi-track
ADAT tracks through a 2" reel to reel, but that only will enhance
things. It won't be as objectively beneficial as starting out with
2" to begin with.
Chris