I have an Onkyo TX-SR706 which has served me well, I have and I am keeping a 5.1 speaker setup that I am happy with.
The problem, of course, is 4K and HDMI. Right now my TV is a 2013 55" LG 3D set (which I never watch in 3D but which, BTW, has a fantastic picture for 2D content). The new TV is a Samsung 2019 75" Q90 that comes with the Samsung Quick Connect box. I have two other quick connect equipped Samsung TVs, one with the mini box from 2017, the other with the larger 2018 box. Neither of those sets, however, is meant to be used with an AVR.
It looks like the video passthrough to the TV via quick connect should be good. I don't need more than the four HDMI inputs it provides (TIVO, Apple TV4K, PS4, and 4K disc player).
The thing I like about the Onkyo is the Audyssey room calibration, which has worked well for me. My question is, if I connect the Samsung One Connect box to my receiver with an optical cable, will everything "just work"? I can fix audio lag (if present) using the Onkyo controls.