I agree, there a a whole lot of knowledgeable people here on the boards who are always willing to help if they have an answer. You'll find that out pretty quick.
The ARB is a really nice unit and it's pretty popular because of it's ability to act like a fully open differential (ideal for icy and snowy conditions, as you mentioned). But you are right, it is expensive and the air compressor required to operate it must be purchased separately and thjen mounted somewhere on board. I would suggest conducting a search of the boards for things like "locker", "ARB", "Powertrax", "LockRite" and other name brand lockers to find discussions about them. There's a lot of useful information here if you're willing to do a little digging.