This is a fun Friday night option. Everyone can get food from the truck they like and you still get to eat together. All the trucks I've been to take credit cards too. A meal and drink at most trucks has run me about $10. Most options are pretty unhealthy, but once in awhile is ok!
I have found it easier to park a block or 2 west of the event, near the train tracks. Seating can be a problem too. Lots of people bring camping chairs. I usually just crowd in at a table or find a curb to sit on. I don't usually go that much after it gets over 100 degrees out though!
Recently there have been merchandise vendors there too. I bought some lotion and soap from a local farm.