Well, the Denon won't even upconvert over component at all, so it's the Zenith for sure. If you can get it soon, you'll get that nice, wide open upconversion over component. No contest.
DVI vs. DVI? Probably the Denon. No white crush there like the Zenith has.
I curently have the Denon 1910 and I'm very happy with PQ through DVI, but that one DVI slot on my RP HDTV will be used for the new HDTV Tivo Satellite soon. I'm going to buy the Zenith to compare... where can I be sure to buy the Zenith without the firmware upgrade that prevents upconversion through component?
There are a few recievers coming out to fix that problem. Outlaw and Marantz are 2 to start with. The Outlaw will be under $1k and the Marantz will be $1500 but it has a stellar list of features. I'm really interested in the new Marantz.
Also there are a few sets with 2 DVI/HDMI ports on the back.
Greg, several of us said this to you at AVS and I'll say it again here. Kick the HD Sat box down to component video and plug the Denon 1910 in via DVI. You won't lose a thing, you'll save a bunch of money, and your DVD player, which I'm sure you'll use plenty, gets optimum performance.
I agree with EricWem, I haven't compared pq between DVI and component on the 318, but the fact of seeing 1080i over component and how beautiful the picture is, I think using component for your HD Tivo receiver would look just as good as if you were doing DVI. I think until HD-DVD is mainstream, the best benefit is using DVI for your upscaling player, most movies will look great and you have a choice of movies to watch in 1080i. HD Satellite is not upto what it should be as far as programming and my understanding that there are still compression issues with HD over satellite. Remember it may be a digtial signal but I believe it's still processed through a analog signal and then sent through a digital signal to your HD receiver.