We love that they added the locking option, the spout is much easier to drink out of then the previous versions, our ice stays in the mug overnight.  I love cold water and this mug is not only pretty, but so functional.  The top handle makes it so easy to tote the mug with us on the beach, and everywhere I go.  It doesn't leak in my purse either.   Just want them to make it in a pretty green color.   I do like my Contigo mug with the rubber where I hold it, easier grip, the curve on this Cortland where you hold it is very helpful too.   Keep up the great work Contigo!!  My cupboard is overflowing with Contigo mugs in all varieties!