glass beaded vs video spectra 1.5

As a temporary solution, I have a tripod-mounted glass-beaded da-lite screen. The previous owner says it has a gain of 2.0. It is 70x70, and looks pretty darn good when driven by my NEC vt540 at 1000 lumens.


But it's only temporary, so I am shopping for a pull-down screen. (A fixed screen is not an option). I'm considering dropping down to the Video Spectra 1.5 because in certain scenes I can see the screen texture on my glass-beaded screen. I have to go mail order because there is no place in town that I can demo these screens. I've tried to read everything I can about these screens on the internet, but before I make the purchase, do you guys think this screen will work for me?


Here's the video spectra:

http://www.shopcousinsvideo.com/dalmodb60x801.html


There is also a matte white screen - I assume this has a gain of 1.0? I'm afraid to drop down to 1.0 gain because the walls/carpet of my HT are all white and I can't change that, so I worry that ambient light will be a problem. Please tell me if the matte white has such a superior picture to the 1.5/2.0, and I'll consider it. I've done the foot-lambert calcs and I come up with:


(lumens * gain)/ square feet


1000 * 2/ 32.5 = ~60 fl


vs


1000 * 1.5/32.5 = ~ 45 fl


vs


1000 * 1/32.5 = ~ 30 fl


Is 30 fl too dim? Anything else I should be considering.


thanks.