I just got my 2910 yesterday and ran it through its paces. I haven't yet calibrated it with my DVE disc, but I can already see and hear the improvements over my Samsung HD-931.
First off, my connections are:
* Component video using the default mode upconverted to 720p (haven't tried DVI yet since my set's solitary input is already being used)
* 5.1ch analog audio with digital output turned off
My first impression is that the audio this player produces is light years beyond anything I've experienced with my HT before. I've got a mid-level Yamaha receiver that I thought was fantastic before using the Denon's DACs. I can't believe there is so much of a difference between the two. The soundstage is more precisely defined and I don't get listening fatigue at even above reference dB levels. I actually feel like I was missing the true theater experience without this player - and underutilizing my Klipsch speakers. I know why those "audiophiles" spend so much on pre/pros and amps now.
To answer one of your questions, I did notice a little graininess in some of he dark scenes in "Eternal Sunshine", but nothing that I thought was out of the ordinary (i.e. something other than natural film grain). What bothered me was the color banding in that DVD. There were many dark scenes that were only lit by a spotlight, producing a stair-step of color instead of a smooth gradient. I haven't compared this to my old player, so it may well be an authoring problem or a DVD technical limitation, but I've never seen this on any other DVD. Overall (without calibration), I didn't see a large difference in video performance between the Denon and Samsung except that there was definitely more shadow detail.
Also tried a couple of SACDs and a DVD-A which didn't overwhelm me, but I did hear the appreciable step up in quality. This is not a feature I see my family using much, but it is nice to have on those occassions.
I just wish I had time to tweak it and play some more titles, but I'll be out of town until Monday... bad timing to get a new toy
BTW- does anyone know of generic Denon discrete codes that might work on the 2910 (or any specific ones)? I'm thinking about auto/film/video modes and pure direct memory modes in particular.