I've compared both M7 and NFB7.32 side by side. It's not just the vocals, although vocals is a good / obvious test. The NFB 7.32 has a weird raspy grainy treble quality and lacks bass pitch differentiation, i.e. "thud, thud". (These characteristics are typical of every SABRE DAC I've heard). I wouldn't even say the NFB 7.32 is one of the better SABRE implementations. A "proper" implementation of the SABRE chip only mitigates, not eliminates its weirdness. From Invicta, NFB 7.32, Oppo, X-Sabre, ODAC, Teac, Mytek, etc. I've heard and directly compared them all under the same conditions / using the same equipment.
The only thing good about the SABRE is detail retrieval without the need for multiple chips.
Edited by purrin - 12/17/13 at 11:38pm