This could go here or in the Winter Bikepacking forum, anyway. I'm in the process of getting a fat bike, it's a rolling chassis and amongst the kit I need to complete the bike are brakes.
The bike won't be my main off-roader but will be mainly for winter use. Note that here in the UK "winter" is probably closer to what would be termed "shoulder" seasons in the US, we don't get that many days below freezing and outside Scotland days below -5C are even rarer but I've also entered the Rovaniemi 150 and it's likely to be pretty cold around the Arctic Circle in February.
So what would be best in terms of brakes, mechanical or hydraulic? My other mountain bikes have Shimano XT hydraulics and my CX bike has TRP Spyres so have experience of both (my old commuter bike had Avid BB7s so know those as well) just not in very cold weather. Searches bring up polarised (unintended pun, sorry) views - who would have thought that of the internet? - with some having bad experiences of both systems and others having not had any problems with either. Local bike mechanic reckons BB7s as they are easier to service trail side but TBH I have found them a little bit fiddly at times.
Thoughts bikers please!