For anyone who ever heard the difference between the sound characteristics of the 30 series and the higher 40, 50 or ATR60 series decks, they could tell you about the added headroom and quieter electronics of the higher series and the very real sonic benefits that those higher lines enjoy.
There's also a nice benefit to direct drive capstans that don't require belt changes, since this is one of those dreaded parts and procedures that many 30 series owners at some point, get to enjoy the experience of changing.
They might also talk about little things like RTZ features that actually work with far less drift of the actual 00:00 position. That being attributed to the superior transport design both mechanically and electronically.
They might also boast about the ceramic capstan shafts which never need demagnetizing or how they drive the backing side of the tape, contributing to less drop outs and wear on your tapes.
As a 38 owner who also owns an MS-16 which shares many of the same mechanical and electronic designs of the ATR60 series, I can personally attest to the fact that there is a definite sonic and overall performance difference that should only be ignored if one wishes to keep their head in sand.
Cheers!
