The Optoma WU515T has a maximum resolution of WUXGA (1920x1200). That's over two times the resolution of the most common native projector resolution of WXGA (1280x800).
A WUXGA (1920x1200) native projector resolution is actually the best resolution across all projectors that are a comparable age to the WU515T.
Across similar types of multimedia projector the worst resolution is XGA (1024x768).
We think you might also be interested in some of the other projectors that have a resolution of WUXGA (1920x1200) currently available including cheaper data projectors such as the Panasonic PT-EZ590 (£2,726.40).