I have to say I like them - cleaning and drying is awful.
I use a full Walmart brush kit, boiling water and Clorox. Its still a big chore, but the stuff that comes out is worth it, both black and white bacteria from the cracks and crevises of the bladder. You just can't come home, toss the pack in the corner and flop on the couch. You half to empty and dry. Even clorinated water goes bad.
I found spring water less drying to the throat.
Just venting here....
Woo