i have the mw80s and they certainly keep my feet from getting frozen, i was really suffering before i got them, i cant imagine i would want a warmer boot, but your feet can still get cold but not frozen after 3-4hrs.
I would say that upto the ankle they are waterproof, however as with most boots, if its raining the water WILL run into the boot, nothing short of duck taping them to your legs will stop water getting in. Also the ankle ‘seal’ isnt all that so if you stand in a puddle over your ankle you could get wet feet.
I dont tend to ride in the rain so this isnt really an issue for me but i do ride in some serious slop and i’ve not had wet feet yet.
The important thing for me is that they are not too heavy or bulky compared to some, I really like them and would buy them again.