I have been using the one eberlestock sells. I have used them for about 2 yrs and they have done ok. I like the valve on them. It has a cover and doesn't leak. I dont find it annoying to have to take off the cover.
They Seem to be tough but i did blow one out. Started leaking right where the hose connects to the bladder. Had to use a lighter to try and "weld" it back. It still leaked but at least I could keep water in it for a bit.
I am rough on my gear..... Liked it enough to buy another though.
I like how heavy duty the material is.
That's my concern. I hate that feeling when your back is suddenly wet and you know you've blown a bladder out.
I haven't been so lucky with my eberlestock bladder. I have had it for 2 years now. In it's defense It doesn't have a bad flavor. But two things bother me, one, the mouthpiece leaks slightly and the mouthpiece cover is so big it will not fit through any of the loops on my backpacks shoulder straps, causing some contortion difficulties to get water at times. I am in the market for something else.