I read a number of reviews about the size of this bag.  I have to say it was actually larger than I expected.  I love all the zippered compartments.  This is perfect for touring and traveling.  Instead of lugging my day pack all over the place I can keep my valuables (passport, ID, credit cards & money) comfortably with me along with a bottle of water and some energy bars.  This won't replace a big day pack but it certainly is a whole lot lighter and easier to carry while taking tours.