There are so many bad suggestions on this thread, I don't know where to begin.
Are receiver is an aggregation of:
* Room Correction DSM
* Power Supply (often the most overlooked part in value priced gear).
In addition, for analog sources, the source is also a critical part of the equation as well.
Each of these in the whole chain can and do have an audible impact on sound. Saying there are people here with racks of equipment who swear by emotiva is a baseless statement--there are more people here with racks of more expensive gear and the so called 'hi end' amps that some people have issue it. No there is no great conspiracy by equipment manufacturers and dealer to con you from your hard earned (maybe
If you cannot hear the difference between an 500USD denon receiver vs a 4.5k Arcam, I would question the source, the speakers and finally your hearing as there is a difference. The measurements used as ammunition to show that that Arcam unit is worse than a 500 denon is part of a review--if you bother to read the review, you will see the reviewer praises the AVR600--so what gives?
My suggestion to the OP is just listen--if you can't hear it for any reason, no reason to buy the expensive gear--I know that I couldn't tell difference the same way I can and I did switch to cheaper receiver for a while and then switched back.
Incidentally Denon, Marantz and Mcintosh are owned by the same company--if you get a chance, you can compare the receivers of Denon and Marantz and amps by Mcintosh. Additional you can look at $500 denon vs a 2k denon vs a 4k denon. The feature list and physical look will be more or less identical but the great differences will be the power supply, and the preamp and the DAC. So the even the engineers within the same brand are also out to con you?
if you can't tell the difference--you are lucky that you will save a whole lot of cash.
Just listen and make up your mind