I can't really comment on the bike gloves thing (just throw the woolly or fleece gloves on over my bike ones - what can I say, I'm cheap...), but in my snowboarding experience I found my mitts (which, alas, died due to the kind of significant structural integrity failings only brought on by old-age) were much easier for manipulating bindings and such than the gloves I replaced them with. Just less bulky I guess. The mitts were certainly much easier to get dry!