Yeah it definitely is a big pack. During the fall/winter here in the PNW I carry a lot of layers. I'm also Type I Diabetic so I carry some emergency supplies that I (hopefully) never use and most people don't need to bother with.
Lately I've been really liking the Jurek Endure. That plus an Amp handheld (squish it up and bungee it to the waist pack when empty) have been great for up to about 15 miles this summer.