OK, I was @ JFK the first weekend of February, and I must say, it exceeded my excepectations by 400%. I did not deal with a SINGLE cop, I was shooting early in the morning from the customs building lot which is pretty good for 31R although the weather was garbage, and the Customs police (not the Port Authority police however) didn't tell me to go away or anything. The whole weekend saw the 31 runways in use, not the 22's/4's or 13's so I guess I was lucky. After spending an hour at the customs building and shooting a South African 737-800 on delvy, I went down Rockaway, passed the 22 spots which are totally legal to shoot from, so to my knowledge PANYNJ police ain't going to bother you there, although the NYPD might, and went to a Costco store parking lot, which was horrible, the aircraft come in too high for me to call them good shots, although for a 747 it's a neat angle. After this I decided to check out the BA terminal, I was sceptical if they were going to let us airside but they did, and we spent the rest of the day and the whole final day there, and it was GREAT, no one bothering you, some pax asking why you take photos/etc, a good food court with a NICE deli place with good corned beef sandwiches and yes, a McDonalds. The seats in the lounge were comfortable, and although some of the BA workers who looked to me like new arrivals who didn't go to far into the city to get a job, they stuck to JFK were giving me some bad looks, i just smiled at them and kept shooting. Sometimes, PANYNJ policemen walked through the terminal but didn't say anything, I think it's possibly a total misconception that cops at JFK hate spotters, maybe if you go on top of the parking garage where you can **possibly** shoot a missile or something at an aircraft, or when you park your car ON the 13L bridge, then they don't like it, but if you are obeying all of the rules and not disrupting ANYTHING, in fact giving money to the food court, then they will be accepting. The 2nd day however, a buddy of mine did me a HUGE favour, flew all the way from Tampa and took me to a great spotting location, but it's not open to the public. I also spent a little bit of time at the Delta T3 looking over 31R, which is fine in the VERY VERY early morning if there is shining sun. Overall a very very good weekend in New York, EWR was decent I shot a few good shots there, but JFK was paramount, not as busy as I expected (even less busy than YYZ my home airport) but definetely had a great variety of Int'l aircraft and the BA terminal was great for the whole day as it's south of 31R. I am definetely returning to JFK again, hopefully soon as I'm now a really big fan on the place. BTW, if you do get told to move on, I've heard money helps!
About LAX, never been there but I do plan to go, originally this March break but I think I want to take advantage of some KILLER Virgin Atlantic fares from JFK and spend 5 days in London, 2 in New York. I will DEFINETELY go to LAX though as I've heard it's a great airport. IAD is also on my list of airports to visit, but after that, I'm scratching my head for good US airports (did MCO/MIA in the winter, and ORD in the fall, DFW is coming up this fall, and I did MSP a couple years ago with some of those shots on airliners.net) possibly PHX or LAS or SEA or BOS.
But, for the question of the summer trip, I'd choose JFK!
Think before you type!