I have and I don't believe it saved me any money. It was an interesting read, though. You can find out pretty much the same information by reading the DIS boards and allearsnet.com.
i bought it and it saved me nothing..then i went back to get the free updates for our trip this year and it wanted me to purchase it again...it was supossed to offer free updates for life..nope it doesnt..i was a few days after having it a year that i tried to update it too