I upgraded my bladder in my Nathan running vest to the Geigerrig hydration system a couple months ago. The pressurized system wasn't holding the pressure and Geigerrig was totally awesome with warrantying it and had the replacement to me quickly! It is an awesome hydration system since it is pressurized, which means you don't have to suck to get your water! I would highly recommend their system if you are looking to replace your bladder in your pack!
I would love one of their Rig Guardian packs. It would be totally awesome if it was customized with the Spartan Race logo.