I tried playing on the Wii online.
i didn't like it. It just seemed the same and I didn't even bother.
I don't think the games that offer wifi don't offer new content as opposed to regular gameplay. There's not much to do (Without using Homebrew or something) playing things like Animal Crossing and Brawl, especially because there's lag. Mario Kart Wii, RB3, and MH3 are more of the ones where it's just like playing a normal game but with others. I would prefer wifi for games like WarioWare, New Super Mario Brothers, Pikmiin, Wii sports/Resort, and, hell I dunno, because they seem like games that can add on more material