In reply to Tony Naylor:
breathability suffers, but ventile dries out quickly, and even when its wet it doesn't feel clammy.
its not a warm garment, but it is a comfortable one even when its wet and cold - its a bit like Buffalo, it seems mental, but it works.
its best in dry/cold environment - like a Afghan winter - where it was just brilliant - but even in a wet/cold environment, like a Falklands winter, it keeps a decent amount of rain/sleet/snow out, and is surprising comfortable.
it can, if kept wet, rot - but thats a couple of weeks with no wind and lots of rain.