>>63857916 (OP)I owned several of these at different points over the last 30 years. I used a set of modern backpacker leg gaiters to keep water and crap out of my boots with all the following: The British poncho was heavy waterproofed canvas, worked really well in light to moderate intermittent rainfall, above freezing weather, and sub 20mph winds. The waterproofing was original, didn't do well in heavy rain, sustained rainfall (think PNW). Wasn't long enough to do well covering a backpack and my body, and was somewhat short, so long gaiters/rain pants were a must. Almost a heavy windbreaker style canvas, so worked well as a outermost layer imo.
I still own my Polish shelter half, fucking love it. Has been treated with aftermarket scotch guard, has all the benefits of the British poncho, but longer, works better over a backpack, and has better waterproofing/resistance. Absolutely needs leg gaiters to keep water off your legs/feet in heavy weather. Lighter canvas, lighter overall, and just plain longer. Might just be me, but I'll make a small fire, use a stave or couple of sticks to spread out the front, and half wear it as a heat reflector to warm up/dry off without making a huge camp.
I also had and gave away a version of the German shelter half. Heavy, original waterproofing was shit, and didn't keep scotchguard treatment. Odd angles meant that it kept the rain off if it was coming from directly above, but any wind and you were wet and cold. Not worth the weight or space given other better options.
Sold my old Canadian poncho, all the downsides of the British, as well as being stupid tight around the neck/face flap. Designed for chicknecked manlets, absolutely no way to wear it over heavy gear.