I had Marantz SA-15S1, and currently have NAD M-55. My recollection of Marantz was warm and soft sound. On the other hand, M-55 is one of the most dynamic sounding player I've ever heard. PRAT is top notch. Midrange is grain free. Bass is tight. It throws a tall and wide soundstage. My current reference Bel Canto PL-1A sounds more airy, but when it comes to PRAT M-55 is the one to have. If M-5 is anything like M-55 you'll probably like the sound.
