Truman, we had an email conversation about this, but I'll post some comments for the benefit of others who might be interested in the projector.
The recent report from the Phoenix Expo mentioned that Seleco was demo'ing the projector on a 72" diagonal screen, which should tell us something about where Seleco thinks the best performance is.
http://www.avsforum.com/ubb/smile.gif I'm using an 82" GrayHawk and it seems to be just fine. I wouldn't mind just a tad more brightness (which is probably why they're using a 72" at the show), but I have no complaints. I think 72" to 92" is probably the zone where you can use a lower gain screen like a GrayHawk.
What I don't know is how far you can go up in size with a white or high-gain screen. Maybe someone with a large high-gain screen and a HT200DM can comment here. Is 100" too big, even with a high-gain screen material?
WRT the internal line doubler:
It's better than I thought it would be. The projected quality depends on how good the NTSC signal is, and this varies tremendously. On my Dish Network satellite system, most of the sitcom channels look like 2nd or 3rd generation VHS tape dubs. It's pretty soft. We watch it anyway on the big screen, because the dialog carries those shows. It still works even with a fuzzy image. But movies are pretty painful, when they're running high compression.
Once in a while they'll dedicate what looks like full bandwidth on a movie channel (they tend to do this more often on the premium and PPV channels), and this can look surprisingly good. I watched a 480i movie recently on TMC-W ("Shakespeare in Love"), and I swear it looked like a non-anamorphic DVD! So the internal line doubler is good. It just doesn't have much to work with, most of the time. Garbage in, garbage out... and sometimes you get lucky.
Another thing... you're going to like line-doubled NTSC a lot better if you have a smaller screen. All the problems with NTSC are related to image scale, which is why the sitcoms that look bad on the big screen are just fine on my 27" TV. I can just barely stand watching this stuff on my 82" screen, at a reasonable (14 foot) viewing distance. I don't think any outboard line doubler or scaler is doing to make the NTSC video look good on a 100"+ screen, especially if you're sitting close to it.