We're going to agree to disagree about 4 wheel drive having any substantial assistance for stopping. If you need to use it to stop you're either following too closely or going too quickly. There is no question that 4wd is an advantage in certain circumstances and when used appropriately. My farm truck has 4wd and I wouldn't have it any other way out there. I have never had 4wd on a daily driver though and seriously doubt the few times it might come in handy outweigh the reduction in gas mileage year round. Also do you really think all those SUV drivers from some suburb barreling down the highway are using engine braking? I suspect that in most cases 4wd is just causing them to be unnecessarily reckless. Streets are almost always plowed within 12 hours of snowfall at the latest. I just don't see that there's any justification for 4wd for the vast majority of people who have it in Minneapolis/St. Paul and like I said it probably causes them to be reckless.
I am firmly in the camp that you can learn appropriate winter driving skills in a sedan and be much better at getting around than all the idiots with fancy SUVs who don't know how to use them. I also believe that's the majority of SUV drivers.