My friends and I consider ourselves pretty good players, but we don't play tournament-style, preferring a loose, "fun" game (though we still keep items off and stay away from the most gimmicky stages). Even not being tournament players, we all liked this mod in its "release" form (version 3), enough that we play it exclusively. They did a wonderful job of taking what makes Brawl great and combining it with the elements that make Melee great, without making it a dry experience that only top-level players can appreciate. We liked the new level set too, mostly for including Hyrule Caste for N64 minus tornadoes. There's also alternate uniforms, most characters from Melee (and all from Brawl), and some completely new moves. How'd they hack all this in?!
In short, no need to be a tournament-level player to enjoy this one, and it's worth the trouble to get it working on your Wii if you play Brawl with others (there's a hackless version available). While YMMV, we think it's an improvement on Brawl for multiplayer.