@madbean , Is there really any reason for a parent to attend, other than to be “sold” on USC? As an alum, I know USC. As a parent, USC has already thoroughly impressed us with the welcome week, convocation, homecoming and graduation. I was just going to “mail” him over there on his own. Do many parents do that and does it hurt him in any way if I don’t attend?
It is not necessary, but… it is a really nice event. USC’s goal for Explore is to say quite clearly–USC really wants your kid. After months or years of helping our kids do well in HS, and driving to ECs, and the challenge of helping our kids select a list of colleges and, of course, watching them get their hopes up as they send off applications to a lot of reach schools/programs, this is a fun switch-up. All of the speakers (USC Admissions, professors, heads of Schools, even Security and Health) will compliment you for raising this kid. Sure, they are trying to get the parents to fall for USC, and it really works, too. 
But it’s also a time we were able to ask straight questions about admissions (the reps had no reason to be politely vague, since our kid had already been admitted) and learn more about opportunities. For instance, USC has a lot of Undergrad research funding through the Provost’s office, and freshmen are eligible. They also fund a wide variety of personal/independent Summer research–and perhaps a kid wouldn’t hear all that when they are nervous about their upcoming interview. I got to hear anecdotes from professors about specific internships (and how they led to employment), how freshmen got assigned to certain production roles, and other details you can’t find on a website. I like a lot of information, so perhaps this was just me.
If the cost isn’t prohibitive, it’s really enjoyable to mingle with the parents of other finalists. I was extremely impressed with the cohort of finalists and it was encouraging to think many would be among his incoming class. We were seated at the parents’ dinner among all the other parents for our son’s major/School and that was interesting in itself. Each of their very accomplished offspring had applied to–basically–all the same reach colleges, in addition to USC. As I enjoy hearing such stories, it was fascinating to me to learn what else was going on in admissions that year.
But as you’ve been to USC a LOT, and this is a 3rd child… maybe you really don’t need much more of this hoopla. The kids really don’t interact with their parents at all, so no one is at a disadvantage without parents on the trip, except to help expedite travel if your kid is absent-minded, nervous, or hasn’t had a lot of independent travel in the past.
@madbean , Don’t get me wrong. I LOVE the hoopla. I would really love to go, especially since my husband got to bask in most of the schmoozing the last time when #2 son was welcomed. But it is just an unnecessary expense at this point. If I were within driving distance, of course I would go. But, since I have to fly, I can’t justify it. Really impressive, though, that they will comp half my son’s flight. That is so cool. And, yes, there is NOTHING like a USC event for welcoming parents. I remember when I graduated from USC in 1991, my dad called the event “underwhelming”, MY, how things have changed over the last 20+ years! Graduation day was impressive! No one rolls out the red carpet like USC.