I've been running the 33" size for years on my 80. They are very quiet for a mud tire. Good road manners.
They are a really good compromise between a tire that can handle the slop and still drive you back home. They aren't a swamper, but are still very grippy.
In the last year I've noticed they've taken a lot of cuts and chunks out of the tires. But, I've taken them to Moab, beat the piss out of them, and drove 'em back home again. Plus, more abuse on rocky terrain here in Iowa.
Snow- Well, good thing they're on a 4WD vehicle. They have no siping and (I think) would handle really poorly in 2WD. They do have large lug voids and will dig through mild snow quickly.
Mud- They do fine. Not as good as true swampers or the like. But you wouldn't want to drive on swampers for hours either.
Note on air pressures- Mine are either D or E load rated (I forget right now...) and take a LOT of airing down to get good grip. This is probobly the single biggest detrement to the tire. I have literally wheeled on a tire with ZERO air pressure and not noticed any ill effects and only minimal sidewall bulge. As they get more and more broken in ( or used ) they get more pliable. This year (4 years on the tires) I now air down to 15-17 PSI so I can still get to a gas station safely to air back up. But seriously, you can still drive on them with 2-3 PSI with little issue.
If it's true that they are now offered in 35" sizes, I'll be buying those when the 33's run dry.