It's completely dependent on Super Shuttle. It could be a half hour. It could be 2 hours. It depends on how many other people they are picking up, where they are dropping off, etc. I've been on a Super shuttle for 40 minutes from SNA one time; another time it was 2 hours.
This is why I'll never do Super Shuttle (or another shuttle) again. Uber or Lyft all the way! It's cheaper in the long run with 2 or more people, and you get prompt, door-to-door service. If you've never used them before, there are coupons/ discount codes for first riders. For Uber, the first timer discount of $22 off basically gives you a free or almost free ride.