The PowerLite 1751 ($649) and 1761W ($799) offer 2,600 lumens of brightness, and thePowerLite 1771W ($999) and 1776W ($1,099) offer 3,000 lumens of brightness.
In addition, the PowerLite 1751 features XGA resolution, while the PowerLite 1761W, 1771W and 1776W all feature WXGA widescreen resolution (16:10 aspect ratio) for use with widescreen media and laptops. They also have a 1.2x zoom that requires a shorter throw distance, so a 60-inch image can be projected from only 4 feet away.
To see all the specs, click here: http://www.epson.com/cgi-bin/Store/jsp/CorpProjectors/Home/UltraMobile