quite a tough question, as I’d been using a Meridian CD player in between selling the Marantz and buying the Luxman. I also only ever listened to the Marantz with the matching amp, whereas the Luxman has always been used with the 509x.
ive found the luxman a big step up in quality. everything the Marantz did well, the Luxman does better. Wider soundstage, less grain, deep bass, clarity, and wonderfully musical. not as laid back as the Marantz but never fatiguing. The amp has way more control of the speakers, the Marantz was a bad match with the triangle speakers, but really performed exceptionally with Focal.
if I were to have the Marantz pair again, I would use focal speakers.