mittens are warmer, great for east coast nights, but gloves in the spring and for pipe and park, cause they are alot easier to grab with and cooler for when your hiking.
Mittens are warmer But I find there harder to grab w/ so I wear a pair of grenade rouge status spring gloves when Im riding and mittens over them when Im on the chair. Unless you o no poles then only mittens will work but w// poles I think its harder to grab