I cringe thinking about bad weather attacks but like an ex-wife that refuses to die it's something you deal with. Having said that if mid - `41 is still considered early war I use weather to my advantage in 1.03 and have slammed several convoys, and escaped unscathed while black swans search about.
Using the best boat for the job, a VIIB btw.
One absolute difference GWX has over other mods I have noticed is the enemy detection. Even trying to sneak up on a single merchant in calmer sea's is more of a challenge but not undoable. If someone plays the game right from GWX without trying a carrer in stock or another mod first I think they experience some frustration in playing a slower paced PC game. Just an observation, and according to my ex, I've been wrong before.
TII's are still your friend on I/P.