I don't know much about Neopan but there are major differences between panchromatic and T-Grain films. Each has it's own "flavor" when printed. In my experience most pan films are pretty much the same within the same asa rating and most T-Grain films are pretty much the same again within the same asa rating. That is to say TMAX 400 is pretty close to Delta 400 when you stick it in the enlarger. If your friend was having problems with contrast there is probably something he is doing that he shouldn't.
On another note, why do you use so many different developers? If I were you I would find one that you like and learn how to tease everything out of it with whatever film you finally decide to standardize on IMHO.
Good luck and let us know how the Neopan works out.