I have a Rivers West Jarrett jacket that I use for wildfowling as I don't mind having mud on it, and it folds down very small back into a rucksack when I'm reentering London. It's brilliant at keeping out the cold and wet, unfortunately is also keeps the wet in. After a mile or two of walking through mud carrying all my gear, I'm pretty damp inside it, which is unpleasant when you cool down. So they're primarily for sitting still, but not a great choice for anything active. I wear my Musto "technical tweed" coat for other forms of shooting and that's what I intend to wear for stalking. It's warm, waterproof, breathable, quiet and pretty insconspicuous. I just don't like getting that damned Kentish clay on it which never comes off, and it doesn't fold down easily.