I bought this for my wife and the 600mL model for myself.
As I mentioned in the other review, the handles on the 600mL version can be a tad uncomfortable when full of heavy stuff but with the 450mL version it doens't get heavy enough to cause discomfort.
This is an excellent product, lightweight and durable, the insulating walls is very welcome on a metal mug.
This review was written in the old system and had content requirements that are different than reviews written today.