Aerosoft is talking about traveling to the United States to personally photograph the airport, FSDT is probably using photos available elsewhere. Mathijs has mentioned more than once about being detained at US airports, guess all that gray hair makes him look like a terrorist.
I hadn't heard or read about them thinking about comming here to take pics of KJFK or KLAX for that matter.
Personally, I don't know why they would even bother to make a version of anything that FSDT has done. It's more like FSDT should remake some of the stuff that Aerosoft has made, then we could be assured of good FPS and not having to mip maps the textures ourselves.
I guess I will have to go take a look in their forum to see what they are saying about trying some US airports. It's funny that about a year or two after FSX first came out, I posted on their forum about doing some US airports and Mathijs said the usual about not getting access, etc. and I was kind of bummed about it. Mind you this was before FSDT really got cranking on US stuff. Now that I have all the US FSDT stuff, there is no way I would buy any Aerosoft renditions after some of my experiences with some of their work. That's just me though, but I think they have a LONG way to go before they get into the same league as FSDT when it comes to making airports and optimizing them to work well. Plus with some of the new stuff FSDT did with KDFW and are planning for KLAX, it's probably way over their heads to do all the cool stuff FSDT is working on.
Just my .02
POST EDIT: I just went and too a look thru their forum and didn't see any discussion on them considering JFK or LAX. Can you point me to the thread so I can see the remarks?