tim,
IMHO,
if you are mostly playing DVDs, then is sure is nice to have a wide screen.
check out
this thread for a long discussion on screens, but my advice is to spend $12 and go get some blackout material and attach it to your wall to experiment with the distance and ratio ideas.
since you don't have a HTPC (home theater pc), then don't worry about POWERSTRIP. And unless you have a computer nearby, eliminate the SERIAL cable issue as well.
I use an RGB connection (which means a plain old cable that attaches any PC to a monitor - and one is included with the projector, but it won't help you out unless your DVD player has a DB-15 on the back) because I hookup from my HTPC - I cannot speak to the 'cinema mode via rs232', but I can add this from my Enterprise viewing this week:
During the commercials, if I pressed the upper right button on the LT150 remote, then screen would go into WIDE mode on a 4:3 commercial, and it would stay there when Enterprise came back. If I pressed the button during Enterprise, then I would get Enterprise in a different size, narrower and more true to what is was supposed to be in - I played with both modes and it didn't really make a diff. I was picking up OTA (over the air) HD and it CAN and WILL be different from you watching via DISH and a UPN affiliate vs. watching with an antenna.
So, don't worry too much about any of this until you get your unit and try your component cable from your DVD player - because there really are a ton a variables and its so much easier to just see what you have when you put a disc in or tune into an OTA source.
Believe me when I say its a great picture to watch OTA HD broadcasts, so plz don't limit yourself to only DVDs... consider an antenna and that makes you consider a settop box (STB) that can handle OTA as well. Oh well, all that costs lots of money... the screen can be cheap @ $6/yard!
best of luck
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Jaymer...
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AccessDTV (antenna on digital input, Tivo on analog)
HTPC, P3 933 (still having DVD playing probs)
NEC LT150 (awesome)
Homemade Blackout cloth screen (from Joann's Fabrics, $6 per yard)