I stick with 12x12 because there aren't many (any?) 10x10 albums available to put printed pages into. I can't say for sure now, but there weren't any when I last checked, a few years ago. When I do vacation photobooks, I change up my sizes depending on cost and page style. (My pocket pages tend to have lots of photos and journaling, so I stick to 10x10 or 12x12 for photobooks with a lot of pocket pages.)