Originally Posted by T/BE20/G
Most everything else has been well answered, but I don't think this point has... AA is spread over 2 terminals at SAN, but it's not strictly Eagle vs. AA. Terminal 2 has all of American's mainline flights, as well as Amrican Eagle RJ service to SJC. The commuter terminal houses American Eagle service to LAX only, whether you're taking an RJ or a Saab to LA.
Simply put, Eagle service to LAX will be out of the commuter terminal, all other AA/AE service will be from Terminal 2.
I think Eagle has some other flights out of the SAN commuter terminal (maybe Santa Barbara?) but that's a very minor quibble.
Only thing I wanted to add is that, if you're new to the SAABers, keep in mind that the overhead bin is very small on most of them (340B). They do have a few with a somewhat larger bin (340+B I was told by a FA). I fly international routes a lot, and always go SAN-LAX-whatever. I usually have one rollaboard and a backpack with my laptop and other essentials stuffed in it (it's designed specifically for my Mac 15" PB). On the 340 it won't fit in the bin unless I empty some pockets, so I either pack light or bring an empty plastic bag. On board it takes a few seconds to empty an outside pocket into the bag, then put both in the bin. Reverse after landing, while waiting for the door to open.