I know OneAlex added some stuff on top of GWX, but I'm not entirely sure what.
I'm currently running GWX Gold with a couple of mods on top of it, I had been running OneAlex but he tweaked the AI to make them laser-guided. Perhaps a good player can handle that, but I am not a good player.
Anyway, so far I've found the following to really help, graphically:
- Merchant_Fleet_Mod_3.3 (and skins)
- TKSS18 German U-Boats Compilation
- OLC's Modified Searchlight Beams for GWX3
- M.E.P v6
- Sh3_volumetric_clouds&fog_V2.2
- Rbs_SH4_effects_GWX_30_71
- Waterstr+Exhaust-CombiV2.3
- Wooden_Lifeboats_Mod_1.1
Not a graphics mod, but the sounds in Thomsen's Sound Pack V3.2cg are great.