I'm kind of new here, but have seen the .8 gain BD II in my local a/v store with an Anthem projector. Their setup was with 100" fixed screen with complete light control. In my opinion it is a very nice screen, but not perfect and probably not the right one for my projector. My only nitpick was the picture from an off angle really darkened out the far 1/3 of the screen, although for most rooms this wouldn't be a problem. The black levels were great and the black bars although noticeable though not a distraction. Star Trek still looked spectacular and I sat and watched for about 1/2 hr.
I'm also trying to decide between similar screens, but in the 100" size for my room. I was told by SI that the 1.4 gain model is more suited for my Pioneer projector. I have a hard time spending a couple grand or more on a screen sight unseen, so the Firehawk although it has a good reputation would be nice to see how it performs in person.