I don't know about the Marantz you mentioned, but you might want to think about what's important to you. What do you want access to, what type of user interface do you want, will the device be supported for the next xx years, do you want a display - and if so, how big?
I've been looking around at what to replace my "old" Squeezebox devices with. Been looking for at least two years, and I still can't seem to find anything that doesn't add complexity. Seems as if the vast majority of people who do stream, are not all that interested in sound quality, or interested in using anything but their phones, and some half baked free app loaded with adds.
In my case, I want a device that does not require a separate display to see the device menu functions and album art, and it needs to be large enough to see without too much trouble. It should also have a simple remote, or touch-capable. It needs to have access to numerous streaming services (not all do), and I also want access to my FLAC files stored on a network drive. Then there is the software needed to play my music files.....some media players just, well.... suck.
I wish Logitech would have stayed in the game. The Squeezebox devices were simple, easy to use, and worked reasonably well.