[CCIP]

They just take a different approach to realism, detail and atmosphere. Neither is necessarily "more realistic", but they take a different interpretation of how to achieve their brand of realism. The easiest explanation is that NYGM is "more hardcore" - there's fewer little graphical and purely atmospheric additions compared to GWX, less (arguably more realistic) traffic, it punishes you much more severely for being too "gamey" with your tactics, things like stealth, detection and evasion are much more difficult. You will spend less time sinking ships and more time evading and surviving. Convoy attacks in NYGM are a significant time investment - mostly because once you are detected, you can usually expect literally hours of trying to lose the escorts, even in good conditions. It's certainly not everyone's cup of tea, but very worthwhile to try!