I built a Parkland screen last winter. After a few months I bought some blackout material and stretched it over the Parkland. A few days later I took down the blackout material and and am still watching the Parkland.
The colors on the blackout were a tiny bit richer, but overall I prefer the crisper, brighter picture I get on the Parkland. I'm using a Hitachi 5500. Different projectors will probably give different results. And also, I guess it depends on what kind of picture you like.
