I've tried GWX with 8km default and harbour lite but it still stutters, don't know why but I suspect the graphic updates! NYGM also stutters but I think it is my cpu that can't cope with the 16km visibility mod...
NYGM doesn't have an optional 8km visibility mod that's why I'm stealing the default scene.dat (8km visibility) from GWX!
My computer is on the very low end but I could play stock SH3 with no problems in harbours and in bad weather... No I'm not able to update the computer but I wanna play too!
I have not yet had the time to test this theory of mine, maybe tomorrow!