My sister got one of the summary booklets while I got the "expanded" which was the same as I've always gotten when there wasn't a choice. As to the differences I don't remember the specifics but it seemed like hers was about half the number of pages and was missing what I considered important info like her transfer info or such...
I thought Disney had goofed up her booklet at the time (April) but now I realize it must have been the summary version. I'll always pick the extended from now on...
Edit: my sister was not happy with the short version and wasn't aware that she selected it during online check in.