I like mitts. Way warmer and can be relatively thinner than gloves so less bulk. You can actually push buttons on a walkie talkie and all that just as easy as with gloves. Another thing I like to do is wear a thin “spring glove” or “park glove” and wear mitten shells over them.
Well I like be able to move my fingers around so I use gloves… One good thing to do whether you have gloves or mittens is to wear glove liners under the actuall glove and try to find a set of gloves with the strap that goes on your wrist. That way you can easily take off your glove and not worry about losing it and then zip down your coat or wipe off your goggles or w/e you wanna do and still have some protection (from the glove liner) on those cold/windy days.
Prefer gloves just due to the fact of I like moving my fingers independently. But may pick up a pair of Mitts next season due to the fact my fingers practically froze at the top of the mountain a couple weeks ago -14F with 20mph winds is pretty darn cold. And I heard mitts are a bit warmer.