That's a moot point actually. Whereas the air-cooled engines undoubtedly develop 'hot spots' in traffic, the rider is usually blissfully unaware.I personally like that they went water cooled for the monsters again, keeps them cooler in traffic and appeals to more people but that's my opinion.
they quieten them down then new owner puts the loudest exhaust he can find on .:naughty:Yes it is easier to keep engine noise down with water-jacketing. And mandated drive-by noise limits are becoming more stringent all the time.
It is also easier to get stronger performance, as water-cooling keeps the engine components more stable, permitting closer tolerances - particularly between piston and bore. This also permits water-cooled engines to run 'cleaner'.
But of course water-cooled engines are generally heavier than an air-cooled equivalent. And have a vulnerability to radiator damage or coolant loss which doesn't affect an air-cooled.
So you win some, you lose some..