Being relatively new to the projection/screen game, I can't really speak authoritatively on this, but I'm going to say it's probably part "brand" and part 'law of dimenisiong returns'. The uber expensive screens may test/measure out better in a lab than the less expensive screens, but it may be at a level that is hard to see, if at all, but most definitely does not give you gains tied directly to the increase in price(i.e: screen A costs 5x more than screen B, but is only 5% "better"). I bought an Elite Screens 120" UST CLR screen for ~$1300. Screen Innovation's version is over $5000. There is no way in the world the SI screen can give better performance in any objective or subjective metric that makes it worth spending ~$4000 more for. Do I believe the frame and overall construction is better? Without a doubt. But there is no way the performance, even coupled with the better construction makes it a good value at 4x the cost.