FWIW, I'm buying the McCormack. It's phenomenal. Better on CD than tha ARC CD3 which was my prior one-box benchmark (and bests my Rega Jupiter, and the Musical Fidelity A5CD I demo'd), better on SACD than the Krell SACD Standard which was my SACD benchmark. DVD-A 24/96 shows are as good as I remember them through my dCS. Nutty piece of gear for a steal of a price, especially because I can get it for about $2700
Unfortunately I won't have time to compare with the Denon 2910 and 3910 this weekend, but maybe in the future.
FWIW, the Denons have some widely accepted mods available from Walter Lieberman of Underwood Hifi (Chris Johnson of Sonic Frontiers fame does the work). The 3910 is available now, the 2910 should be soon. The McCormack player I am buying above is essentially a hyper-modded Pioneer DV47, and judging by it's sound quality the Denon mods should be a great value. So you'd have an upgrade path, so to speak, with the 2910 or 3910.
There are 3 issues with mods, tho: 1) you don't get the fancy casework and build quality of a better piece, 2) no warranty anymore from the manufacturer--this may not seem like much, but in the realm of hifi I have *never* had to pay for a warranty repair on gear I bought new, even years and years down the road. 3) resale value on modded units is tough to pin down, and usually sucks.
But if you're not a gear hound that buys and sells often, modded players can be sick values. Something to consider as the buy-in for a Denon 2910 is only about $700 IIRC.