I've got and have used a variety of brands of avrs (currently have two Denons and an Onkyo in use, a Sony on the shelf and had a Pioneer that failed), and the whole assigning of a sound signature thing isn't a thing IMO/IME. Particularly silly when you think about how wide a variety of models brands offer (or how many times the brand has changed hands) and the various contractors that build them to assign a "signature" sound to the brand itself.
In their basic pure direct output they're all going to be more similar than different. Their room eq/dsp can make them sound different, many like the Audyssey setup Marantz/Denon avrs have (Onkyo used to have Audyssey as well, and I have one of those units, but has instead inserted their own AccuEQ which doesn't get very good reports), some don't care one way or the other and don't use such. I'd simply shop for features and connectivity and maybe worry about whether the avr is suitable for 4ohm loads.
You might ask Hsu if they have a brand preference, which I somewhat doubt, but believe they use an avr for demos.
I've had good experiences with A4L themselves, some of the refurbs provided by the factory (which in itself is a misnomer as brands tend to hire a contractor for service/fulfillment than literally send them back to the factory) not so much in that I had two Denon refurbs fail, but A4L stuck to their end of the deal and was easy to deal with. Buying a refurb does have a certain amount of risk but most of the reports I've read have been good experiences.
