Very good, but not the best!
I had bought these thinking they were the best upgrade to water bottles since ice and YES, they are great, BUT they present some of the same issues other water bottles have.
One is that it could be softer *cough* (Specialized Purist) and two is that the nozzle is a nuisance to clean when used with anything other than water, thus reducing the life of the bottle and possible growth spots for mold and funk. Two stars off for each of those and a little hint for the consumer.
Check the Capo bottles in the bike section?