I've got one of these - bought direct from Canada (where they're based, not the USA although the prices are in US$, IIRC)

It's good - I use it quite a bit. To answer an earlier question, yes you can definitely rear project, although they're quite susceptible to hotspotting (a bright spot close to the angle of the beam from the projector), so careful projector positioning is important.

For such a big screen, a fairly bright, short throw projector is useful. I use a 3000 lumen BenQ short throw job, although to be honest on a couple of occasions it's actually seemed too bright - illuminating the whole room!

One point to note is that because it's not rectangular you lose parts of the image at the edges (if you use the whole area to project onto, of course... which does look best). It doesn't matter for visuals and most music videos, but with slideshows, photos, etc you can find you lose people's heads if they're close to the edge of the image. This also means there's a fair amount of light spill around the edges, which projects past the screen and onto whatever's behind/in front of it (ceiling, walls, etc). Whether this is a problem depends on the shape of the venue... and how fussy you are