The Aid button is way faster, and whatever algorithm they use to choose what building gets aided is reasonable. GBs and special buildings seem to get priority over residential buildings, supply buildings, cultural buildings, and decorations. Also, even if there are no buildings to aid, you still get the coin reward for aiding. I can't recall, but don't think you get it when you physically visit the town and choose a building. About the only reason I can see for spending the time on visits is to be able to choose the age of the building you want to aid, since that determines the age of the GB BP you get (on the off chance you actually get one). If I remember correctly, there's only about a 1%-2% chance of getting a BP, so you've got to be more than a little OCD to spend so much time on such a minor reward, IMHO.