The Yamaha is working fine. I’m just considering switching to the Anthem. Looking for something that is a bit more musical I guess. I haven’t heard anything about the new Anthem piece so just wanting some input.
You might have come to the right, or wrong forum depending on whether you tend to believe more on the subjective based audio myths or objective based specs, facts and figures supported by bench measurements.
The fact is, the more expensive AVM70 may have features you need that is not available on the CX-A5100 and it may have a little lower distortions than the CX-A5100 has distortions and noise level well below what may be considered audibility threshold, so there is no reason to believe it would be any less "musical". However,
Anthem's REQ likely do work better than Yamaha's YPAO though if you are willing to spend time to tweak with the PEQ for the Yamaha, you may get very good results too, according to Gene and other users.
THD+N is not the only criteria obviously, for more test results take a look of the following (the CX-A measured better than the CX-A5200, some of the results are included in the review of the CX-A5200):
Anthem AVM 70 Preamplifier-Processor Review - HomeTheaterHifi.com
Yamaha CX-A5200 & MX-A5200 Measurements & Conclusion | Audioholics
CX-A5100:
Brown: Unbal - 90dB @ 1kHz
Red: Bal -95dB @ 1kHz