sun devil, it's really what you think is worth it to you. To me, Denon's higher end reference series ABT2010 video scaler (with more controls for video calibration and better upconversion capability), along with a full color onscreen GUI, a slightly more powerful amp and 5 hdmi inputs are worth it to me.
At the end of the day, it's what features you are looking for that matters. You can't go wrong with either the 1910 or 2310. In saying that, you can get a great deal from E Expo (as I did, over 25% off the retail on the 2310). Mine will be arriving today and can't wait to set it up.
Good luck in your search. PM me if you want info on how to get the best price.
LG 55EG9100 (HT) * Denon 2310CI * Fronts: Energy XL-26 * Center: Energy XL-C2 * Surrounds: Energy XL-16 * Sub: Velodyne VA1012 * PS 3 * HTPC
Panny 50PZ800U (bed room)