Artograph Prism projectors...Yet another question

Question

I have noticed that Artograph do another type of projector the 'Designmaster' range which allow for horizontal and vertical projection of the image, where as the Prism only allows Horizontal projection.... My question is this... Why buy a Prism then ?, when the Designmaster is a more flexible tool at about the same price. Has anyone actually seen a Designmaster in action? I don't want to buy a Prism and then find shelling out ??150 for a vertical stand to go with it. when the Designmaster does it just as good without buying any stand. Bloody h**l that was vague...but u get the point I'm makin' I'm sure :-) Wenz