I even had 2 different units of DX3 Pro and the P50 LPS.I have the Dx3 pro and the M500, and I can't hear any difference between them...fwiw.
On my IEMs: DX3 Pro had no bass, M500 totally fine.
On my 58x: DX3 Pro had bass, but didnt extend as low as M500. Voice was presented in front of music. M500 presented voice more as part of the music with fuller bass.
There was clearly and audible difference.