Ryan Collinswrote a review of Platypus Big Zip LP Hydration Bladder on November 7, 2018
Familiarity: I've put it through the wringer
The wide zip top makes it easy to fill, dry and clean out. Easier than any other brand. The snap attachment for the hose is a great feature. It makes it super easy to replace any part that may wear our over years of use (hose/bite valve).
4 stars since you actually have to pay attention to closing the zip component. As mentioned below, do a quick inversion test to check you sealed it correctly.