As far as I'm concerned the smoke screen boundaries mod is by far the most effective and useful mod ever created for WoWs. I use several mods like changing the AP HE shell color, moving things in the GUI around where I like to see them. After SSB the second most useful IMO is the simple yet critical labeling of ships on the mini map (instead of just showing a generic DD or CA BB symbol you get Mahan, Baltimore and Iowa instead with the symbol) as well as showing the last know location of an enemy ship.
I can live with out the latter but not having the Smoke borders REALLY effects my ability to play as a gunboat and get the absolute max effect from each smoke screen.....mine and others I scavenge. Whomever came up with that SSB mod is a genius in my book. I really do appreciate all the work the modders do...Aslain and everyone else. You people really make my games so much more enjoyable...and every time I start to forget that Wargaming drops another major patch and I'm reminded...... :-)