I ended up cancelling my USC actually after speaking to students from USC while on the interview trail as well as after talking to people who had already interviewed there. Reputation-wise, its not regarded that highly and underwent substantial turmoil in the past few years. Currently, it remains IMG-attending heavy (which you can see by looking at faculty on their website) and didactics could use improvement (apparently it is common for residents to give lectures rather than attendings). People from USC have often complained about the downtrodden facilities (especially in the county hospital, which lacks air conditioning in the summer), but hey, it's still in southern California. Hope this helps.