The Benq MS502 has a maximum resolution of SVGA (800x600). That's 39% less resolution than a XGA (1024x768) data projector, which is the most frequently found resolution.
A SVGA (800x600) native projector resolution is actually the worst resolution amongst all comparable spec projectors that have been on the market for around the same time as the MS502.
The best resolution across comparable types of projector is WXGA (1280x800).
Alternative projectors that have a resolution of SVGA (800x600) currently available which you might also want to look at include the Benq MS504 ($308.99) which has a better Rating; or the Acer X11 which is cheaper.
If you would prefer a data projector with a higher resolution then you might also want to consider the DX346 (XGA (1024x768 and higher rated) and higher rated), or the DX325 (XGA (1024x768 and higher rated) and higher rated) both from Optoma or the Benq MX505 (XGA (1024x768 and higher rated) and higher rated).