Thanks Mark. I guess I was hoping that there had been some definitive testing showing that one type has a better overall net heat gain.

So are all blankets now "bubbles to the edge" instead of the flat edge seams like my old one has? I know we have to tug pretty hard when pulling the blanket off the reel, and imagine popping a lot of bubbles as we grab a handful of blanket.

Since it appears I'll have to get a 20x40 blanket, and cut it, are there any tips on cutting? I assume I'll just cut one side after letting it sit on the pool a couple days to see how it settles.