The main improvement is in HDR -> SDR conversion. So its play back of 4K HDR material on early adopters of 4K TV's which dont support HDR. Also projector owners where I believe HDR can cause issues (but I dont have a projector, just going on stuff on the 203 owners thread). I havent tested this, but probably also for owners of 1080p TV's as well.
I believe the player has been pretty solid if you have the latest generation 4K HDR tv's.
I personally cant see any difference playing 1080p or lower ie Bluray or DVD. But then I thought that looked pretty good from the get go.
Yes - you can set it to output LPCM through its HDMI port to an HD621 or UHD722, from any format (disc or data stream). This will keep your Meridian stuff happy and relevant. BTW, I have heard this player through its analog outputs as well as through my G68XXD via HDMI (LPCM). The Oppo is good, but the Meridian is still better.
Just bought a UDP-203, wasn’t planning on getting one just yet as waiting for the 2018 OLEDs before upgrading my beloved Kuro screen. However as my Denon Blu-Ray player is starting to have problems reading some disks thought it better to get an Oppo now while definitely still available.
Other than setting HDMI audio output to PCM, are there any other settings needed to ensure I get the best 5.1 sound from my Oppo/Meridian setup? Eg downmixing, speaker sizes etc?