Magnetar 800 or what for simple surround/Atmos system.

I have started collecting some BR and DVD releases for surround/Atmos playback via my Sonos ARC/SUB/Era 300 TV system. I also own many SACD's that I play on my Luxman D-10X in 2 channel but would like to experience the surround versions as well.  I currently use an older Sony player connected to my Samsung TV HDMI eARC input then via digital out to the soundbar.

But I think I want a newer player and am looking at the Magnetar 800. I think the 900 is not needed as I am not using any analog outputs.

Am I wasting my money? What other choices do I have? Obviously this is not a high end setup but the Sonos system is pretty darn good for surround stuff.