I have one but stopped using it. I drink a HUGE amount of water on long hot humid days and need something other than two cages between refill spots. I just went to carrying the equivalent amount or even more than would fit in the bladder in regular bottles in the backpack. Easier to fill, more flexible in what I can carry, and cleaning/replacing/refilling random bottles is much easier and quicker. I don't miss the convenient drinking tube either. I place my active bottles in the regular cages and pull them out while riding as needed and swap or refill them with full bottles out of the backpack. Not against it but if I'm carrying something on my back for the long haul, I want more flexibility.