The PT-RZ570BEJ has a maximum resolution of WUXGA (1920x1200). That's over two times the resolution of the most frequently found native projector resolution of WXGA (1280x800).
A WUXGA (1920x1200) native projector resolution is in fact the best resolution across all new projectors.
Across comparable types of multimedia projector the worst resolution is SVGA (800x600).
It may also be worth also looking at one of the alternative data projectors that have a resolution of WUXGA (1920x1200) currently available including the Panasonic PT-RZ570WEJ (£3,369.67) which is cheaper.