I haven't ridden the 3DS, but i can tell you about the Covin:
Fast: This board just wants to scream to the wake. You sometimes have to reign it back in. It really gives you the chance to have a board that wants you to push it.
Landings: Very sold landings, also quite forgiving on the landings.
Versatility: This board can easily pop you vertical, or launch you to the flights, allowing you to vary your trick execution. The fins also allow you to keep a very solid edge, but it can be playful as well.
I am extremely happy with my Covin.