I own one and I agree entirely with your review. Have you seen the trendy travel mugs that people use? I wanted one of those to take to the cinema while on holiday as my friend already had one. I couldn't find one like his anywhere, so I bought the 0.35L Thermos instead as it holds the same amount (a decent mug size). The travel mug types differ only in the fact they have no cup, are wider at the top (easier to drink from) and they have a secret stash compartment in the lid to put in a spare tea bag and sugar. Anyway, my friend and I compared temperature half way through our movie.....mine was lip scorching hot, his was just about drinkable. Also, even the people who have bought the uber-trendy and expensive 'Lifeventure' and Brugo' brand travel mugs have complained of leaks.....nothing like that from my Thermos. The only thing they have going for them is they are slightly smaller (the cup part on the Thermos adds height), and I really like the little compartment for extra tea bag/sugar. But hey....I can live without them while knowing my drink will be hot (or cold), and that it won't leak on me.
I must add, too, having a cup of home made tea half way through a movie in the cinema is the very definition of civilised! I highly recommend it. Just don't let the ticket collector spot it on the way in. :)
One thing gets me, though. How on God's great earth does the flask know whether to keep your beverage hot or cold? I don't see a switch anywhere. ;)