Have you decided between LCD or DLP? Have you decided between 4:3 or 16:9 projector and screen? The Z1 is 16:9 and the other 2 are 4:3. I don't think you should consider the S1, it doesn't even have a zoom lens. You should also consider the X1 and Benq 6100. I have the X1 and love it. Go to Projectorcentral.com and read away, great site. You have to narrow down your choices to DLP or LCD, then 4:3 or 16:9, and go from there.