Arrived yesterday with car at PNF. The PNF shuttle driver told us that they're treated like any public traffic and cannot use Bainbridge which is for on airport use only. He said because of that, it can take 20+ minutes at peak traffic times.
We'll stick with PNF for now. There are discounts for Frequent Parkers, AAA, AARP and discount codes all over the Internet including Groupon. A quick search wil get you at east a 15% discount off their $10.95 rate.