I work has a Freight train driver, so I needed something that was going to be pretty good and would keep the hot water hot over a number of hours. I read the reviews and thought I would give this ago. I have the blue 750ml flask. Looking at the flask its distinctive, the color is bright and stands out from the rest. I've been using this flask for around 2 weeks now and the hot water stays hot up to around 8 - 9 hours. Up to the 12 hours mark, it's still hot but the edge has been taken off and tea or coffee can be a little cooler with milk added. This is a pretty good flask. It's a little on the expensive side, but it's some different to what the other guys use and for the extra, I like something a bit different from the rest. I've not used this for cold drinks, so I can't comment on that. Would I buy another one....Yes....Marks out of 10.....10 out of 10. The only downside, I wish Chilly could make 1 litre Flask...