I have only flown into/out of long beach. The smallness was both a good and not as good thing. I like to sit down for a meal and/or drink at an airport AFTER security, so this is the one and only lack I found at LGB.
As mentioned the security is super easy and every one is so relaxed. Traveling with 2 young kids, it was no big deal to go through security, nor did I feel rushed by the people behind us (to be honest there was no one behind us, we were the only ones in the entire security area)
The rental cars are all directly accross the street (100 yards from bagage claim). All companies share the same building and parking lot,I would say there were/are 5 different rental companies. No need for a shuttle to the car.
FWIW, last april we got a mini van rental for 9 days through a name your own price company for $311 tax and fees total.