I'd recommend Playa D'en Bossa. Space is there, short distance to Amnesia, El Divino, Pacha, Privilege & DC10. Bora bora is in PDB, plenty of bars and resteraunts open at any time of day! The longest beach in the whole of Ibiza! Less lager louts than in San Antonio (meaning less trouble). A good mix of english, irish, spanish, italians, germans, polish, french, people! Ease of gettin 'stuff'. Plenty of bars with TV's if you are over there when its the football season. Less PR's compared to San Antonio, PR's are people trying to hassle you into going to the bar they are working for. Oh and the final selling point is that Playa D'en Bossa is only about 10 minutes drive from the airport, while San Antonio is a good 45minutes!
So come to Playa D'en Bossa! I've been last summer and this summer (got back a couple of weeks ago) and I will certainly be going back to Playa D'en Bossa!