What's the R/inch? What's the price difference? What did they use to blow or create the bubbles? Is it an ozone reducing chemical? One brand may be just trying to make inroads verses the other if all of those things are equal. Could be as simple as how far away is the factory, or newer production techniques. Basically, I don't know, but a little research into the spec sheets should tell you. If space is critical, the greater R/inch may be worth the difference. Otherwise, it really doesn't matter...it's not like you're going to be looking at it...it must be covered up with a fire rated covering anyways.