We went through SJC (BA 279) on 12/31 for the first time and it was relatively easy having Global Entry. There was a BA rep just outside the plane door asking folks if they had connections to give them on-going gate information. If you know what you are doing, I would just keep going to "keep your place in line". From the plane, it is quite a long walk through narrow corridors to the immigration hall. They have 4 Global Entry stations (one was not working) and 3-4 manned stations. We were in FC but because they deplane out of the mid-J door, we were maybe the 15-20th off the plane. It is a little chaotic once you get to the immigration hall as you turn the corner and the GE machines are just on your right. It was hard to know where you should line up for GE because it could block the folks trying to get in line for regular immigration. Part of the problem was that there was a family that was using two of the GE machines and it was probably their first time so they could not figure it out.

Once you get your GE pass and go through the GE line at the immigration desk, it is a short walk to baggage claim. Once you get your bags and go through customs, you are now landside and can either go straight to exit or to your right is a very small re-check bags for connections area. (The same BA agent that was at the plane-side door was also hear assisting.) There is also a security checkpoint for reentering the terminal for connections. As at many airports this checkpoint DOES NOT have Pre-Check. If you are Pre-Check, you could just go out the exit AFTER rechecking your bags at the re-check area and enter Terminal A regular security which does have pre-check. This might be better for you since American leaves out of the A Terminal gates. The advantage to the international security filter is that you can take the elevator just past security up to the Lounge at SJC (if you have access).

Bottom line, I think that SJC is better as long as they have enough immigration stations open. LAX is almost always a zoo. Best of luck.