I've been using CamelBak bottles for a while, and I feel they're the best ones I have. I've used many others, but the spouts on these by far are the easiest to use because you don't have to close them every time you put your bottle away.
For me, this is such a great design. You can just leave the bottle in the open position while riding, and it won't spill out, yet you can still drink from it with a little squeeze. One less distraction to worry about while riding.
Comparing this to prior version i miss the waist where one can get a good grip on the bottle. When putting it back in cage that is a helpful feature to know you are close to the top of the bottle. Otherwise nice smooth screwcap and pliable sdes.