The speedmaster and America are not solely air cooled in that they both have oil coolers as well. Rode a 03 America in the tropics for 3 years and nil signs of overheating at any point. Have previously run a air cooled HD in the same conditions and it did not like it at all. Most HD owners retro fit oil coolers in those parts. Obviously you have a tad more engine noise compared to the water cooled but not that great.
