It's interesting what you say about printing...I am still using 12x12, at least for the 2013 book...I may change my mind for 2014 when I get the final price for my 2013 book!
While my computer monitor is large, it does not show a 12x12 square when full sized, so many times when I print, I encounter brads, staples, titles and other things that are somewhat too large
I've tried to be more careful, especially with brads, sizing them down to something like a 1/4" or 1/2" at most.