I have a Denon DVM-3700 that I bought as "B-stock" from an eBay seller. It's been a very reliable unit. I have bought many things that are "b-stock" and have had excellent luck except with one NAD tuner. In fact, from a high-volume (compared to high-end producers) company like Denon, you are usually better off in that you know that your specific unit has been fully tested, as this is standard procedure for a refurb unit. With first run units, they usually just pull a few off of the line from time to time for quality control. I would go for it.
BTW, I've really liked the quality of my Denon, both as a DVD player and as a CD-transport. I recently bought a Theta David which betters my Denon significantly, but retail on the David was $4500 and retail on the Denon was "only" $1200. (Of course, I got the Theta used on eBay for $700 and paid only $300 for the Denon refurbed on eBay, too!