what kind of hydration packs do you guys use or like? ive been using a kole gear hydration pack since molokai and i really like it. i like that you dont have to wait to get the water, its right there when you bite it. i also like how you can fill it halfway up then freeze it overnite,then fill it the rest of the way up and your drink will stay cold for the next few hours. any input or opinions would be greatly appreciated.