Welcome back BigEd!
I do my layouts in 8.5x11 and print them borderless to put in albums of that size.
Paper scrapping is traditionally done in 12x12 and I think that has carried over into digi-scrapping. There are alot of folks who will scrap in a square format, usually at 12x12 and print at a smaller size (8x8, 6x6) due to printer limitations (except for those lucky people who have 12 inch printers).
To a certain extent, I think there may be advantages of using a square format instead of a rectangular one. When working with a rectangular format, I am always aware of "dead space" that I need to fill or work with. I find myself usually using a landscape mode which seems to be more visually appealing than portrait to me, but then I struggle trying to figure out how to lay things out. If the format was square, it would be simpler.
Someday when I get a 12 inch printer I will probably switch to a square format.
Just my opinions!
