I got a 4805 from costco and will be pricematching this week, here's my thread on the costco deal
$999 after rebates includes 76" screen and 30' s-video cable
I'm very happy with the projector. I have about an 11' throw and with a 76" image and am acually sitting about 10' away. I thought it was going to look like crap due to my small room size but I am amazed at how excellent it looks for DVDs and computer games. I've taken a few votes from people I've watched movies with doing a comparison of larger vs higher quality with the zoom and the answer is always larger when I do a demo of the two. This projector really rocks.
If you have to settle for an earlier model, go for the X1 or 4800 (they're the same thing) due to the de-interlacer chip (I can't spell it either heh).
The 4805 has the same chip as you've mentioned and personally I think standard cable looks excellent on it. Naturally not as good as a higher quality signal, but I was expecting crap but I really think it looks good. I'm sitting the same distance for that but screen size for 4:3 is about 60". At this distance I really like the picture.
One thing to keep in mind about the 4805 vs. 4800 (X1) is that it's 16:9 instead of 4:3. Initially I thought I wanted a 4:3 projector but the more I thought about it, the more it seemed like 16:9 was for me. I think I made up my mind when I thought that it made sense for the 16:9 material to be the bigger screen and 4:3 to be a portion of that since 16:9 material is generally better and where you want the movietheater type feeling. There's a good article about the 4:3 vs 16:9 decision
here
I think I mentioned it in my cosco hot deals link, but I got the ATI DVI to component adapter and it works great for playing video and games on the projector. Text is a bit of an issue, but I never really intended to do browsing on the projector or reading anything long.
Well, good luck. I hope the costco deal pursuades you to get it instead of the older models. Oh yeah, I'm sure you've seen the threads here about costco's return policy, but I thought that was a really excellent reason to get it there too. If my bulb blows too early, I know I can count on costco taking care of it.
edit: I feel kinda silly putting these really amateur pics of my setup, but I'll do it anyway in case you're wondering how big you can get in a small space. Again, projector to wall is about 11'
dorm room madness I don't have the screen yet as I explained in the costco thread, but It looks incredible even on my slightly off-whie wall.
edit #2: That's a 36" sony wega in the pics for scale. I should have gotten a projector to start with, but I was afraid of a number of issues that I have gotten over since then heh.