[John Pancoast]

I've done a lot of campaigns in GWX and NYGM. Don't have the machine for LSH.
I haven't noticed much if any difference in AI between the two if one uses realistic tactics and mindset. If one doesn't any AI can be to easy or tough.
Personally, I think the AI in both is so-so, but a lot of that is due to game limitations. I also think GWX isn't just about eye candy; it's plenty "realistic" too and that includes the reasons for some of the eye candy.
NYGM does have some nice equipment/gameplay realism additions vs. GWX but that doesn't mean one couldn't add the same into GWX on their own.

There are various minor likes and dislikes I have in each, but nothing show stopping. Overall I prefer NYGM, but can't go wrong with either.

Both are great and those involved can't be thanked enough.