I know its a stupid comparison, because we all like to see both, but for me personally, a fighter utilizing a boxing skillset over 12 rounds and out boxing and outfoxing his opponent, to me is far more interesting.
I would expect boxing enthusiasts to appreciate a 12 round masterclass more. As it tends to be casuals who jump on the bandwagon, sold by the prefight hype, that just want to see 1 round knockouts and start to boo if a fight goes past 3 rounds.