I haven't been to LAX
for almost a month now, so I can't comment about the security first hand. But I can tell you that the State of California has ranked LAX
as the #1 location in the state most likely to be hit by terrorist. That report was released a day or two ago and I think it will only make things more tense around the airport.
As for the Imperial Hill, It's always open and I would guess business as usual. It's located in the city of El Segundo so you won't have to deal with the LAPD or Airport police. Every so often the El Segundo police will drive by but they never stop. Plus there is always plenty of company at the hill, full of spotters and regulars.
The In and Out Burger restaurant location on Sepulveda Blvd. just north of the airport is another good location to watch approaching jets for 24R. Plus, you can get one great burger. Ask for a Double Double animal style, you won't be disappointed.
And last but not least is the Proud Bird Restaurant on Aviation Blvd. just south of 25L. They have a nice garden with a great view of approaching aircraft for the 25's. If you like you can have a drink or something to eat and watch through the huge picture windows.
As for the other airports, forget about them and concentrate on LAX
. The others are pale in comparisons to LAX