Thanks
@Golfx for that info about Class D amps.
In terms of using pre-outs, I rather avoid that. I will most likely just keep the 5.1 setup, but having a couple more amps to move to either 5.1.2, 5.1.4, or 7.1 would be great.
I really want an all-in-one unit. One that is free of HDMI bugs. Having to unplug things and/or power off the receiver is not going to fly. I don't even have any 4K sources yet (but about to), so I can't imagine how many more issues will crop up with the current receiver.
One of the things you should keep in mind, is that many of the HDMI issues are related to the various CEC, HDCP, eARC handshakes and negotiations that go on between the different components - this leads to a vast number of possible permutations and combinations, with some proportion of them, being disfunctional.
I expect, over time, things will get more "compatible" - but there will be many firmware updates between where we are now, and true plug and play compatibility, without issues.
The problems are just as often within TV's/Projector's, or source devices, as within the AVR's / PrePro's.
There was a recent example of someone with a Firestick connected to the AVR - and all sorts of issues with other sources and outputs... when the firestick was physically disconnected from the AVR, all the other issues disappeared, and the other sources and destinations worked fine.
So right now - it is a bit of "pot luck" - there are no guarantees in HDMI land, and all forum threads for all manufacturers are full of compatibility issues.
Having said that - most people have their setup working fine... but forums tend to be where people go when things go wrong.
I would not expect the HDMI issues "noise" to abate for another couple of years.