That’s exactly how I felt, the M5s is very nice but after hearing and using SR15 it just doesn’t cut it. The layering and positioning in the sound stage is much better on the SR15 and the tone is also better, the treble is more resolving as are the mids.
I don’t think there is much that can compete with it in it’s price range. Especially since it has that musicality and AK perfect timing. And I don’t like too neutral like ibasso 200 or Fiio x7ii either. Build quality is really excellent also.
Sony wm 1A is good but no tidal, and tidal sounds utterly fantastic on SR-15.
Anyways enjoy, and it will get better