sony xa5400es or marantz sa15s2?

I don't think "toneing" it down with a marantz will work.
It's not very musical regardless of dark or bright

I would say from my exposure to both that the Sony is better regardless of system.

Bold statement.Have you heard every system that these players have been used in? Just curious.

I am a musician over 35 years
My ears are very trained
I trust my assessment

I have no experience with the Marantz but for a msrp of $1500 the Sony is an absolute steal imo. My most recent players have been Esoterix XO-3 se, bryston bcd-1, simaudio moon eclipse and MF A5.The Sony doesn't quite have the razor sharp imaging of some of these but is more holographic,more real sounding. Also, tonally it is better than any of these imo( atleast in my system).

A big plus to the SA-15S2 is that it has a digital input, so it can also be used as an external DAC for a music server, etc...