I just went through this myself. I wanted an integrated and was dead set on the Gryphon Diablo 300. Lucky for me, I had a dealer down the street that happened to have two of them for sale. He suggested that I compare it to others prior to buying it. I demo’d that night an Esoteric F1, Krell 300i, and a Luxman 509x. All of these I used the same source (Aurender A30) and speakers (Magico S3).
The prior day, in a different shop I tested the Boulder 866, Accuphase 380 and McIntosh MA12000.
It is hard to compare different things that are not in the same store, so I will just say that the McIntosh and the Accuphase were very close to each other. WIth the speakers and room I had in shop #2 I like the Accupahse the best, but not by much of a margin over the MA-12000. The dealer told me that The Accuphase lacked a bypass mode for HT which I later found out was wrong. The Boulder was painfully bright, I didn’t like it at all.
Shop one all three were really great. The Gryphon which I was dead set on buying I found to be a bit too rolled off. The Esoteric was great but I wasn’t a fan of the sound stage. I found little to no definition or separation in the instruments. The Krell and Luxman were quite similar in sound quality as well as sound stage definition. In the end I bought the Luxman. For me it edged out all the others for over all sound quality, build quality and over all esthetics. For me it hit high marks in every category not just a few.
So if you are able to, find a Luxman dealer and demo the 509x. I compared it to integrateds costing 2x as much and the Luxman was the better unit. Now that is for my ears and my musical tastes, but if you dig into some reviews on it, many others will say the same thing.
Good luck in your search.