i got a camelbak clasic, which has no compartments at all. I take out the bladder and put it in mine compataible berghaus cubic 25 wenn i need storage space. And sometimes i throw that bladder in other backpacks aswell, even though they are not compataible.

Camelback is the best hydration system i tryed. Mine platypus hoser developed a crack on the hose attachment and the bitevalve isn't as comfortable to bite in. I used mine camelbak bitevalve wenn i used to use it. I also bought a source transporter, which i sold, becaus i didn't worked for me. The removable bladder isn't, so it's much harder to clean and dry, the "suck"valve is a bit annoying too....