I bought this mug a few months before my AT thruhike, and used it through the entire hike and other backpacking trips.
Pros: lightweight, strap handle is perfect fit and snaps easily on my pack, better insulation than expected, lid stays pretty secure, easy to clean
Cons: The main downside is that the cup itself has a tendency to slide out of the cloth holder, especially after daily use. I lost this mug a few times out of the holder (and luckily only had to backtrack a little bit because I happened to notice it was gone), which is a big problem when you have very few supplies and everything is essential. I “fixed” the issue by putting duct tape on the bottom of the plastic cup and making it adhere to the bottom of the cloth cover, but I had to redo it every time I gave the mug a good washing.
You can buy this mug from GSI and many outdoor retailers. My buddy Tree also bought one after he saw how awesome it was, and it served him well.
(Top image photo cred: ReviewOutdoorGear youtube channel)