I'm having trouble finding a conclusive response to my situation, of course this is the internet and you'll find conflicting answers but I thought I'd throw this out there. My wife and I are considering removing the plaster and lathe from the first floor bedrooms and insulating and installing drywall.
About our house:
1929, story and a half tudor style near the Minneapolis airport with stucco siding. The walls are currently "insulated" with horse hair and straw. I've heard plaster is a better noise insulator but this is Minnesota and I'd sacrifice noise for heat. We would use 5/8" drywall and probably the fiberglass insulation that comes in it's own vapor barrier.