This is by far my favorite small pack that camelbak offers. It is large enough that if you want to you can use it for a day trip (although its really tight and its hard to fit a jacket in it along with other supplies and food).
I own 6 camelbaks and I use this one the most because it is good for almost anything besides a big day trip or anything longer than a day. This is the second one of these that I have bought, I gave the first to my best friend after buying this years version of it.
I love the organization pockets and exterior pockets and the rain jacket is awesome. The built in rain jacket is such a plus because you can get away with not having a rain jacket on warm summer days (the important electronics and supplies will be kept dry inside your bag).
Not all M.U.L.E.s have a built in rain jacket. Only the M.U.L.E. NV has one, not the standard version.
awesome vest for running and short bike trips. Doesn't hold enough water for long trips (although I don't think a big camelbak does either). Great for what its designed for and it secures down tight to my body with minimal movement as I run. The water bags are located just above your hips so it is a much more stable pack than most other camelbaks.
Although I don't use the pockets for much they are great for storing a snack or power bar. The outer net pocket is also great if you want to carry a light rain jacket or sweatshirt.
works great, keeps my mouthpiece very clean so I don't have to worry about throwing my pack down anywhere. It can be a little hard to get through some of the slots for the tube so it may be easier to just take it off when you remove your tube completely, it just depends on the pack you have. Also when installing it, you need to put the rubber mouthpiece in it, then get it onto the tip of the tube, and rotate it them together squeezing the bottom of both pieces together as one.