I have a Camelbak Hawg that I bought probably 13 or 14 years ago. It's big enough to go overnighting with if ya want. I don't use the hydration pack too much any more unless I'm going on an all day ride, but I sure like to be able to carry my gear and have enough space to stop on the way home and buy groceries for dinner and be able to stow them in there.
Just talking about the back pack it'self for a moment, Camelback is a very well made piece of gear. Both my Hawg and my wife's Mule have served us well for many years with never a popped stitch or a ripped seam.