I mean, M-100 and Q701 is my current stable, and I don't usually bother using a dedicated amp with my M-100. The Q701 scales more with amping though, improved bass impact (same amount of fullness tho) and less treble sheen once you feed it enough current with low distortion. My FiiO E12 works well with either headphone, but other than a slightly sharper bass impact the M-100 and a smidge of better control throughout it isn't vastly improved.
FWIW I had the ALO National and I LOVED the way it sounded with the M100. Super clean, major impact improvement bass wise, overall a great amp for the M100.