Originally Posted by
GrussGott
...
Hard call.
I have both the M4U2 and the QC15 (not the QC35) - the M4U2 runs circles around the QC15 where sound quality is concerned, especially with the amp on.
OTOH the ANC on the QC15 is much better and from what I hear the QC35 has even better ANC. The case of the Bose is also smaller, it might also be a factor.
Probably it comes down to your preference for better SQ or better ANC.