I have a fat bike with 5" studded tires (3rd winter). That beast can handle pretty much anything. If I had to have only one bike to handle anything winter can throw at you that is the bike. With that said I rarely commute with it and primarily use it for winter off road riding and some racing, and I love it dearly. If the snow is piling up during the day I'll commute on the fat bike, but I hate what the salt does to the drivetrain so mostly it's my weekend fun machine.

OTOH, My Cross check with studded 35mm tires and IGH can pretty much handle winter the commute duties with ease and doesn't doesn't have as many exposed parts for the salt to eat up. We've had so little snow here this year that bike choice has been pretty easy. When the snow gets deep it's tough, but otherwise, it's the way to go for winter street commutes.

I'll say this, Fat bikes are pretty amazing, yes, they are a little slower but once you embrace the slight decrease in speed for the fact that you are rolling gleefully through a winter wonderland, all your podium dreams melt away and it's simply awesome. The community of riders, places to ride them and events that are developing around fat bikes is just incredible here. They are making winter riding really possible for a lot of people that would never have even attempted it in the past. And they really are super fun to ride all year. Sure it's a niche of a niche of a niche sport, and haters are gonna hate on them, but they aren't going away.

I know this doesn't really answer the OP question, but it's my fat biker $.02.