IME There are Thermos flasks and then there are Thermos Ultimate flasks. The former tend to be no better or worse than most other flasks, but the latter perform better and seem to me to last longer, too. Their longevity is helped by the fact they have plain stoppers, not the complex, fragile and difficult to clean push button type. The 500ml version I have has been in use every week or so for at least four years and is still going strong.
The Prism isn't really a windshirt at all, but a synthetic insulated jacket, and a very popular one, I would only wear it when walking in the coldest conditions, because it would normally make me too hot and sweaty, and it's not that breathable. The Marmot DriClime has a little insulation, and is much more breathable (and versatile). I've never heard of the Montane DriClime windshirt -- DriClime is a Marmot system and the name is not used by other manufacturers, so far as I know.