My like for S/U came from the fact that Zack Quinto and Zoe Saldana where the actors and they are two of my favourites actors at the moment. Also the romance was done very well considering the fact that it was just a minor plot.
I have always said that S/U is very similar to the Aragorn and Arwen type of romance in the lord of the rings films where the couple get like 5-10 minutes on screen in a 3 hours film but we still get the whole story.
The S/U romance was not a cheesy , badly acted , unconvincing way over the top romance like anakin/padme from Star Wars or edward/bella from Twilight. it was about 2 believable people in a relationship, Which for star trek is how a romance should be.
However I only like S/U together in JJVerse alternate reality which is the 09 film and hopfully in the 2013 film.