Johnfg465vd
500+ Head-Fier
You are going to get a more refined sound for sure, improved details, separation, power... but if you are looking for a direct portable upgrade, why not consider getting R2r DAPs like HiBy RS6 or Cayin N6ii (with R01 board). I've heard the M11 and have read that it has a similar sound signature to M15 but less refined. To me it was a few steps ahead of the RU6 in technicalities, power and refinement but not as musical.Does it worth to upgrade from the RU6 to the Fiio 15 or the Sony WM1A?