Here are the changes to GWX in it's latest release as listed in the manual.
The ones in bold are AFAIK unique and not released before GWX as other mods.
I'm not sure, but I suspect the manual change log is not comprehensive...right?
- The open hatch mod and diving duck's type II interior fixes
- New model for one of the cruisers
- OLC's environmental mod (Tweaked for GWX)
- New and changed radio messages
- New depth charge sounds
- Bug fixes for bugs in the previous version.