Hey Fejin, I've been meaning to respond to your post. I was just accepted to SA's San Marcos campus (but our applications are exactly the same because we still had to submit everything to the FL campus). I feel as though SA takes more time looking at the applicants as individuals rather than the numbers. So to answer your question, my advice on the autobiography is to spend a lot of time on it. This is your time to set yourself a part from the other candidates. Don't bore your reader with every fact about your life; concentrate on what exactly drove your interests to PT. Your statement of purpose will also reflect on your interests in PT, however the autobiography gives you the opportunity to explain, for instance, why you may not have began your college career in a relatable field of study. Good luck and let me know if you have any other questions on the application process.
klp, my numbers weren't as high as a lot of posts of people on here. 3.2 undergrad, 3.5 prereq, 440v550q4.5aw. I was accepted for the Spring trimester of 2012. I feel as though I had very strong references (2 PTs and anatomy prof) and I also have over 1,000 hours of observation because I worked as an aide and observed at a hospital and a snf. My interview went very well too, which probably helped. Let me know if you have any other questions and good luck!
I am so excited and cannot wait to start!!!! 
