Being the cheap bastard that I am, I research everything thoroughly prior to buying them. The problem with isopure, at least the ready to drink kind, is the processing they must go through prior to packaging. The glass bottle requires that the contents go through a process called "retort". This has been shown to greatly diminish the protein and vitamins in the drink itself. Same thing goes for the products put in aluminum cans. Just in case, I always go for the powder version. Besides, you save tons of cash this way!