The highest resolution supported by the Benq MX723 is 1920 x 1200 (WUXGA). That's over seven times the resolution of the most common graphics resolution of 640 x 480 (VGA).
A 1920 x 1200 (WUXGA) graphics resolution is in fact the best supported resolution across all 13000:1 contrast ratio multimedia projectors that are a similar age to the MX723.
A 640 x 480 (VGA) graphics resolution is the worst supported resolution across comparable types of data projector.
There are a number of other projectors that support a resolution of 1920 x 1200 (WUXGA)|640 x 480 (VGA) currently available which you might also want to look at including because of it's better review score, the Benq MW724 (£349.00).
If you want a multimedia projector with a higher resolution then you might also want to look at the MX666 (1024 x 768 (XGA)|1600 x 1200 (UXGA)|640 x 480 (VGA)), the MX768 (£708.01) (1600 x 1200 (UXGA)|640 x 480 (VGA)), or the MW632ST (£325.00) (640 x 480 (VGA)|1920 x 1200 (WUXGA)) all from Benq which also has a higher rating.