I have a similar dilemma and equipment. Oppo 203, Anthem AVM 60, and JVC DLA X550R. I've had my projector professionally calibrated prior to the arrival of the 203 and my picture looks absolutely stunning on all of my devices to include 4k on the Roku. Even after calibration (one of the best calibrators in the business who has done it all), the picture quality is horrible with 4K HDR blu rays. Zero pop, faces are washed out, colors no where near on par with what I get on bluray using the 203 or my Oppo 105D. Standard blu rays look insane as does the 4k streaming from the Roku (non HDR). My cable is Audioquest Pearl and my receipt says 12M HDMI cable. With my calibrator here, no matter what changes we tried to input on the JVC (hence sliding the controls of color, contrast, etc.) it made little to no difference in picture quality. My 1080P blu rays look far superior. Have even tried running Audioquest Pearl cable directly from pj to the 203 which resulted in the same poor image quality when playing 4k UHD HDR discs. I have ordered a Monoprice certified premium 25ft cable just to experiment and see if my cable is the culprit. If that does work, I am concerned that the cable won't be long enough to run through my ceiling and back to my equipment as I've had everything professionally installed. Another challenge is accessing the rear of my projector which is mounted near flush to my vicoustic sound panels as that's the distance the projector needed to be at for the proper throw distance for my dedicated room. I will need my installers to address this. Any assistance gentlemen would be greatly appreciated! So frustrated right now!
Processor: Anthem AVM 60, BluRay: Oppo 105D & Oppo 203, Amps: Rotel RMB 1095 & Rotel RMB 1555, Speakers: B&W 804S, B&W HTM3 center, Atmos: Golden Ear Invisa HTR 7000's, Surrounds, Definitive Technology Studio Monitor 350's, Subs: Definitive Technology Super Cube 1, PowerSound Audio S1500, Projector: JVC DLA X550RB, Screen: Stewart Filmscreen Deluxe Screenwall 2:35:1 screen, Power Conditioner: Panamax 5300EX, Media/Gaming: Apple TV (4th gen), Roku4, Xbox One, PS4 Pro. Remote: Control4 EA1