That thing is the holy grail for insulated bottles. It's easy to drink straight from. The top of it can be used has a cup and works pretty well. It's easy to clean, it doesn't leak at all. The most important part : I think the heat retention is the work of a dark wizard or something. I poured some ice cold water in it and it was still cold after a few hours. Just for the hell of it I poured boiling hot water in it before going to bed and it was still warm in the morning. Scary stuff.
If you aren't afraid of dark magic, I highly suggest you get one of those, it's awesome!
PS: Please excuse lack of proper spelling and grammar, English isn't my first language.