Well I'll serve up my experience with Onkyo.
I had a standard 5.1 AVR, TX-NR609. The HDMI board got flakey. I did some research and sent it off way up to Syracuse, NY from Florida to an authorized repair center, just about at the end of the warranty. I paid shipping to.
I suspect they replaced the HDMI board, so the (bga) media chip and other components (mainly caps) I suppose were as factory new.
I became aware later that Onkyo was offering deals to purchase a later 2016, Atmos capable model for $200 for those that had been through all these HDMI problems. So I bit, I had to strip off the serial number, mail it in with $200 and they sent me a new TX-NR656 5.1.2 Atmos capable AVR, which was my introduction to Atmos.
Never had any problems with it that I can recall offhand that weren't operator error. Good deal? IDK but it got me into Atmos.
Now put away in favor of my new TX-RZ50.
The old NR609, I recapped the board with spec'd, higher heat tolerant caps from the help of a fellow QQ'r and gave it to my Daughter and it's still kicking.