Has anyone got a Grandview 67 ins x 38 ins Pull Down Screen from http://www.walterstewart.com/uk2shop.htm ? on there for £141 inc p+p! are they any good? also.. looking at the OWL screens, people are rating them but are the manual ones as good as the electric ? and what is the gain on them? can't find any details / specs of them on the web.