A
Aerie I use a water bladder primarily and was carrying a crappy single use water bottle to hold electrolyte mix. The HydriamX is far better: I can use it for a sports drink AND hot tea in the morning so I can be eating breakfast and drinking tea at the same time without carrying a 2nd pot. Bonus: Since my old MSR bladder doesn't attach to, well, anything, I can also use the HydriamX to gravity filter water with the help of Cnoc's Sawyer coupling.
Amateur tip: you learn quickly you have to use both hands to drink from this since it's not a rigid water bottle. My first reaction was "oh man that's terrible" and then I realized no, no it's not... it's just different and more than justified by the HydriamX's utility.