The jury's still out
This bladder seems to work well, and I certainly can't argue with how easy the wide opening makes filling and cleaning, but I did have issues on a recent race that was a 7-mile MTB climb. I nearly passed out trying to suck the water out of the bladder--the choice was either to stop and hold it overhead, or go without. I don't know if I did something wrong, or was just sucking too much wind to be able to pull the water, but it was disappointing. I'm going to give it another try to see if I can figure it out.