I know this is an extremely old post, but just was reading around. I wish I would have read this sooner, but, I think I still needed to audition this for myself, lol. Now I have to sell it. Those are basically my thoughts on it as well. I have the RX-A710. I'm only missing out on a few DSP modes, which wouldn't have even helped with gaming. I emailed them. It was a bunch of Hall DSP's basically.
If you really want to audition them then you really just need to try a DH device like a mixamp or tb dss. What you'll get out of the receiver will be better tone controls, absolutely dark noise floor and more power then out of just a mixamp or dss. I recommend the H&K avr-254 or if you have more money to spend then get a Marantz (their lower end receivers don't have DH iirc). I do have a couple issues with the 254 so I have to see if there's a firmware update for it.