Freezing Rain

I definitely have. Seen snow, sleet, hail, and rain all within a few hours coming off a peak. All I had was windshirt and a softshell and once they wetted out I was pretty miserable for several hours after dark. If I'd had any shelter I would have been able to wait out the storm but I didn't so had to keep moving non-stop to maintain warmth. Not something I would recommend trying yourself.

So when I got home I immediately bought an Arc'Teryx GTX Pro-shell I found at a smoking price.

Recently I got a chance to test it out again in similar conditions, a night hike out of a heavy rain in sub 40F weather (I live in AZ and somehow manage to only go out on 6 days a year that it rains and is cold?!). Having the hardshell (and good soft shell pants) made a world of difference. I was comfortably warm and had energy to focus on other issues, like navigating our poorly marked trails in canyon country in the dark ;)

So as others say, a good shell is key and having a tarp to set up as an emergency shelter is key.

Getting a break from the conditions is good for morale, and decision making.
Maybe that is why 'bothy bags' were invented in the UK (I think?). It's amazing the difference a 10 minute break in a warm, sheltered environment can make.

you shouldnt end up a sweat blob if you wear a light synth base layer and a rain jacket with very good ventilation (OR) when hiking … unless yr doing constant steep ground with a pack

to a certain degree i find that the rain actually cools you if you wear minimal clothing

even if you do sweat … you shouldnt be wearing insulation at that point regardless … if yr sweating, move slower or wear less

the less you wear on the move , the less there is to dry out