Black ice is a killer no matter what you're running in the rear end. Best way to deal with it is to learn what it looks like and drive accordingly. No braking, no sudden moves with the steering wheel. Park the vehicle ASAP in the first available safe location. Otherwise you're toast. The only way to safely drive on it is when everyone else has parked and you've got the road to yourself. Even then it's like driving on eggshells.
I don't drive on ice, or even wet roads, if I can help it. But i DO run a mini-spool. It WILL get out of hand if the road conditions change, as PaulS says, but it is all a matter of learning to drive what you have. No different than sitting behind the wheel of a 500 HP corvette...it will get out of hand if you aren't familiar with it's "personality". I have done THAT as well... I am comfortable now with the mini-spool, but there was a time when I ended up looking at the guy behind me when I gunned it. Luckily for me, nobody got hurt, so if you go the spool or lim-slipl route, take it easy until you learn how to drive it.
Go for it ... then find a wet open parkig lot and have at it ... lots of fun and will let you get the feel for it ... safety first though.
Can't say as far as a Maverick as mine is not on the road yet but I have a Richmond Lock-Rite in my F100. It is I guess like a lunch box Locker. It replaces the Side gears and spider gears and is a ratcheting type of locker I guess. In straight line when I give it gas both tires get traction. If I jack up one tire the other tire will pull the truck off the jack. If it is wet and I am starting off in a turn I have to be real careful or the inside tire will lock right up and the truck will fishtail. Not had it in the snow. It improved the traction of the truck 100%.though. I used to get stuck in a flat yard on wet grass. Not anymore. Can be fun though. At a light off the interstate and a lady started blowing her horn as soon as the light turned. We had some freezing weather the day before. I had 2 trucks in front of me so couldn't go anywhere anyway but she blew her horn again. I took the left turn back over the interstate and blipped the gas peddle just a hair in the middle of the turn. My truck has a low compression 460/c6 in it but has lots of torque and it doesn't take a lot to get sideways. Once it stepped out I kept a little gas on her to make it more dramatic. I got up the the next light about 200 foot ahead and looked back and this lady was hovering over her steering wheel and running about 15mph holding up everybody behind her. It can be fun. lol clint
I say peg leg...Had an 83 turbo coupe with posi and going down the road it was foggy\misty down shifted for the light turning red from 5th to second(obviously not on purpose) sideways I went scared the $h t out oof me....Knowing your car is one thing but one mistake and you could be sorry... for a weekender posi. The amount of miles you do for a daily driver the odds are stacked against you that sooner or later life's going to jump out at you. Its not learning how slow to take an off ramp its when the idiot 2lights in front of you just dumped a quart of tranny fluid sittin at his light and you hit into it comin around the bend on a nice sunny day or at least it was a nice day.......
Are we talking a stock type Ford unit with clutches or an aftermarket unit? That might make a big difference in the way it handles on a wet road. I have had 2 trucks with stock units with clutches and they were no where near as harsh as this ratcheting type thing I have in my truck now. clint