JFK is the only addon I have had trouble with. Hence I was wondering if V2 was a bit faster.
If you really had 35 fps minium at other places, and you have 5-6 at KJFK, the only possible explanation, is that something ELSE is causing this kind of problems in the New York area. Most likely candidates are Autogen (the default one around JFK is very slow) and too many AI.
These screenshots compares JFK V1 and V2 on my system, which is far for being the best suited for FSX ( 2009 MacPro with 2.66 Xeon processor + nVidia 670GTX, no kind of overclock). Sure, JFK V2 is faster, but V1 wasn't really "slow"
So, whatever put your fps so low at JFK V1, wasn't JFK.
About OOM, if you followed all the discussions about Vancouver, which some users thought to be a "cause" for OOMs, it was clear that you just can't fault any single add-on for being the cause of OOMs: if your setup for a specific area is ALREADY very close to the limit, because you put your settings too high and use too many add-ons in a certain place, just adding anything more will put you a risk of OOMs, without this being the "fault" of anything.
People usually put the blame on the last thing they bought ( "hey, I never saw this message before installing xxxxx, so it must be it!" ), but since FSX, as a 32 bit app, has an absolute limit of 4GB or RAM in total, and the OOM message comes even before reaching it, if new add-ons comes and users pretend to be able to use them all together, without being prepared to compromise a bit on settings at least, if users don't start learning how to configure their setup, sooner or later nobody will ever be able to install anything else, and OOM will appear everywhere.
With CYVR, we offered the ability to configure the scenery resolution very precisely, and this will help lowering the memory footprint. Using DX10 will also help a lot, because under DX9 a lot of memory is wasted. For JFK, since it's a simpler scenery, it's usually enough to lower the texture resolution in the Addon Manager from 4096 to 2048 or even 1024, and that will reduce the memory footprint of the scenery, so will using DX10, since the scenery is compatible with it.
But if you had OOMs with JFK V1 already, V2 won't help with that. In fact, it even uses more memory than V1 because, as usual in this kind of things, there's no "free lunch" and the faster FSX native graphic commands, also take more memory than the slow and inefficient FS8/FS9 code we removed from V1 to V2. So, the fps will be higher, but you will have to be more careful with your memory.
I'd say that, the same thing that caused abnormally low fps at JFK ( 5-6 is really the *lowest* I ever heard, and it's really a first ), was also the cause for OOM.
And no, it doesn't make much sense comparing other products, because each area is different and the New York area is peculiar, and with 3 large airports in a very short distance (JFK, LGA and EWR) if you have an AI package that works with busy real world schedules, what is killing your fps AND causing OOMs might be those hundreds of AI models and textures in a very small area and this, combined with the already problematic New York default scenery, might be the cause of all your issues.