This is a good topic and I'm sure there will be quite a variety reflected in the replies. I'm old school and it took a very long time for me to come around to using modern technology for cold and wet fishing conditions. I still can be found sporting vintage Lewis Creek wax cotton or my trusty Filson wax jacket but I do own a Simms also.
I like wax jackets and have been wearing them since 1980 when I bought a Hoggs of Fife as my first. They are warm and unless the conditions are extreme or you are camping, they are just fine. The Simms G-3 that I have has been a very consistent piece of gear as far as keeping me dry. My 2 favorite features are the large hood with a good stiff brim to extend over a cap, and the neoprene cuff cinching strap design. I can reach right into the river without getting a wet sleeve inside the jacket.
For good looks in moderate conditions I wear Filson. When I drive an open hulled river boat 70 miles through driving rain at 44* & 35 miles an hour, I wear the Simms.