What I am trying to establish is what in folks opinion gained from experience is what do they believe to be the best coat for stalking in the UK and Ireland where we stalk from the seashore to the highlands or hills.
I suppose i am trying to learn from mistakes other folk may have made.
I'm going to rise to this one as over the last few years I've had a bit of a change in my tactics when it comes to coats.
As with many I came the usual route from waxed Barbours to Gore-Tex. I am well aware of layering and all that stuff but even so it seemed to me like most commercially available jackets were far from a good solution no matter what you wore under them. Now, my idea of a good solution will be different from other people simply because of my use but I fish/stalk/walk about 100 days per year in Ireland and the Outer Hebrides so I experience most UK weather except (generally) the extreme cold conditions of inland areas of Northern Scotland. My stalking and fishing often requires long walks over difficult ground followed by periods of little or no activity, the fishing especially can mean 6 miles of tough walking and then a couple of hours standing relatively still on the loch followed by another mile or two to the next loch and another long stand and then 6 miles back out to the parking spot again.
Long story short what I found, even in relatively wet parts of the UK, was that a completely waterproof membrane often left you wetter, colder, and less comfortable than if you'd been wearing a non-waterproof jacket. I started wearing the British army windproof smock and treated it with wash in, or spray on, waterproofing so that it was showerproof. When you sit and think about it then it isn't many days in the year you are out in constant rain so the windproof smock (or other similar solution but the smock is hard to beat) wins maybe 90% or 95% of the time. When it comes to constant heavy rain then, clearly, a non-waterproof jacket doesn't win and in that case I would put a waterproof shell on under the smock - sounds silly but it means I keep all my pockets, the smock keeps the waterproof layer quiet, it can be quite a fragile waterproof layer as it is protected etc. I've used all sorts of things as the waterproof layer, depending on weather or inclination, ranging from £15 commercial shells and army surplus stuff to my Musto Munro jacket and for me the system works well and I use my brain to determine the right combination on any given day.
What you need to understand with this approach is that, just like layering, it is a system and so can't be marketed as "one solution to all your needs" as it requires you to use your brain - if going out on a lovely day then there is no need to carry the waterproof shell, if going out on a rotten day then it might be best to put the waterproof shell on to start with, if it looks like you might get some longer periods of heavy rain later on then the shell can go in a bag or pocket and be deployed as needed. I know our weather is variable, but I don't think I've ever been "caught out" with completely unexpected weather as the forecast plus the windows fitted to most cars and houses allow for assessment in advance.
It is useful to combine this system with a well thought out application of thermal layers. So if walking hard I'd often wear only a shirt or base layer under my smock but when I stop then I'd throw on something warmer while standing fishing or making lunch. With a bit of thought and common sense you can make yourself very comfortable and completely at home even on the most remote ground in the most changeable weather.