I have a Dalite screen model B. This was bought on the premis of being able to roll it up and down (yeah right)and out of site. I can tell you now that it remains as a fixed screen and looks great (also in basement). Same intial criteria as yourself, my wife wanted the screen out of the way when not in use, but after having the theatre set up for a couple of months...no problem with it being rolled down as the whole system looks quite impressive. (getting new leather furniture may have helped as well)
Couple of things I did that may help.
1. When I mounted the screen, I mounted the screen to some blocks of plywood ( 2" x 5") attached to the wall just to get the screen about an inch away from the wall. This lets the screen hang down without interference (not leaning against the wall) as well as making it easier to roll up if you have to (from experience - doesn't catch on the wall)
2. Instead of tensioners and other expensive solutions, I originally had used bungee cords. However the look was a little less then appealing. Added small "wrist band" weights that joggers use, first to the sides and then I just went to a single weight to the handle. Worked great.
3. HVAC is probably the major culprit in making a screen move, and I had a vent a few feet away from the screen. I got a vent cover that blows the air the opposite direction away from the screen so that I now don't even need the weight attached to keep the screen still. Look for any changes you can make here. This $7 improvement solved any screen movement.
4. Although I have only had the screen for 4 months, I figure at $200 dollars for the screen, if it gets wavy in 2-3 years....just buy a new one. This is the cheapest part of a home theatre!!!
I can send some pics of what the finished product looks like if interested, as I can't figure out how to post these.
