Coming from a G scale garden railway background, I would say anything automatic (either electrical switches, or air-controlled switches) are always more maintenance in the long run. If you do go with automatic ones, make sure that they are easily removable or replacable and you might want to consider bringing them inside in the winter to prevent water from getting in the mechanizm and freezing.
I would recommend remote switches and less is definitely more. Building extensive outside switching networks usually isn't a good idea.