Yeah, I know. I have one of those bladders on the Mason. The Platypus I tested yesterday has a similar middle join. My problem with both is that they have the rigid top piece.
This puts the "lid" on a side and it also looks like it's joined in the middle like the other two.
Lol, bloody autocorrect.
The think that interested me was the bit down the middle, to make it more into two sections, reducing the amount of sloshing