Anyone know much about projector screens?

I was going to build one after getting some advice from our buddy Kex, but after seeing this one on the Monoprice website, I just may pay the $500 or so and be on my way. I like the fact that it's motorized so I can retract it when not in use. I'm assuming the quality is going to be decent, but perhaps someone has reason to dissuade me from this?

For only $467.80 each when QTY 50+ purchased - Motorized Projection Screen (Somfy Motor) w/ IR Remote - Matte White Fabric (120 inch, 16:9) | Motorized Projection Screens w/ Remote Controller

Also, just for the amusement of all those following my projector saga, I ordered the Epson Powerlite 8700UB today, so I won't be watching anything in 3D for now.

Thanks in advance for any advice you can offer.