the 3808CI is heavier, has a little more power, MultEQ XT (vs regular MultEQ), different DAC's and ADC's, Denon Link 3, SACD support over HDMI, and a few more inputs/outputs. the 3310CI has an extra HDMI input, better video processing, PLIIz, and you don't have to pay for the DynamicEQ/Volume upgrade as a "feature pack".
I'm weighing options and considering the 3808 vs. 3310. Can anyone tell me if there's a difference between the two in accessing internet radio? Is there a difference in the GUI? Is there a difference in the ability of the two for access from a PC, iPod Touch, etc.?
If I got the 3808, I would certainly do the $100 firmware upgrade.
I wish I could have both units side by side hooked up to a TV and ethernet so I could see/feel what if any differences there are. I have to admit being pretty ignorant to all that is possible with these units so its hard to know what I may be missing if I were to chose one over the other.