This thermos does keep things hot (or cold) for quite a long time. That aspect of it is great. My one warning is that you should definitely screw the stopper in VERY tightly, otherwise it will leak all over you when you open the thermos. Many times it has looked totally sealed to me, and I've gotten an unfriendly surprise when opening it later. That aspect, not so great.

It's also pretty light, and seems to be durable. My husband takes it everywhere with him, and it's holding up so far.

This thermos is magic. I can make tea first thing in the morning and it is still piping hot mid afternoon. I bought one for my friend who works outside all winter and he says the guys on the job site are always jealous of his hot coffee come lunch time. I haven't had any problems with leaking, either. This is a must have for cold winters.

I was interested in a Sigg thermos primarily because I would like to reduce our exposure to plastic and metal that might leach into our drinks. I understood that Sigg linings are recommended for this purpose. However, I got mixed messages about whether there was a lining in the Sigg bottles for hot drinks. I decided to order and see for myself. Unfortunately, the thermos is NOT lined, as cool drink Sigg bottles are, so for me there was no point in keeping the bottle. Hope that helps anyone who might have the same question.