These are the best damn bottles around. The coating on the inside of the bottle works. Until you drink from one of these you don't know how much plastic regular bottles put in your drink. HEED tastes so much better out of these.
The valve works well. It's easy to turn on and off and when on it won't drip. And you can disassemble it to clean it.
They even rubberize the rim of the cap so you are less likely to drop the bottle. They are a little heavier than Camelback Podiums but I can deal with that.
The biggest problem with these is that the local shops can't seem to get any, and they are expensive. But I recently found out that Excel Sports has them for a pretty good price. They only have clear 22oz and clear and white 26oz bottles, and they have the Excel logo on them, but I can deal with that. The 26oz bottles are larger than the usual 24oz "large" bottles, which is good on long rides... if they fit your frame.