Like everyone said pretty much personal pref. I am partial to Burton boards, Burton boots and Union Bindings (Lifetime warranty on baseplate and heel cup. Plus union is a binding only company so it directs all its energies and resources towards just bindings resulting in some of the best bindings to ever see snow imho)
Union may try to make the best bindings but it doesn't mean they make the best. All because a company directs all its resources toward one product line doesn't mean it results in the best. Larger companies probably have more resources and larger r&d budgets.