Update 4 years later: I have attended and graduated from the University of Southern California with my Master's in Strategic PR in 2020! Just incase anyone has come across this and wants answers/insights...
I used Kaplan test prep. My scores were:
Quantitative: 151
Verbal: 159
Essay: 5
Also, I LOVED MY PROGRAM! I learned so much and grew a lot as both a professional and a person there. I'd say I mainly learned a lot of soft skills and was exposed to a lot of great opportunities and professionals, making it the perfect environment to network. The Trojan Network post-grad helped me get a job in 2020 (incredibly stressful as you can imagine).
Happy to talk more if anyone has any more questions! As an FYI, the program I applied to changed slightly (Master's in Strategic PR was what I got, now it is Master's in Public Relations and Advertising) but I can speak to the overall USC master's PR experience.