Mario Party 5 was the best so far, in my opinion (I still can't get over the fact that both the writing was pretty good and final boss was a better platformer Bowser boss than the one in Sunshine), but yeah, while 6 was a step down (and much less fun in Single Player, yes, I play it), it still had some decent bits, and a couple of nice platformer-style games, which I loved. (Running from the boulder, jumping on the Bullet Bills, the music notes, and of course, the four area platforming sequence one.) I think both a blessing and a curse for it, though, was that there was only one "normal" board. EVERY other board tried some game-affecting gimmick, and while some were interesting (like Bowser vs. DK), every now and then you wanted just a differently-themed normal board, even if it would've been the type of thing done before.
What I don't get, though, is that they're including another Mic with this one, right? That makes two mics if you're an avid Mario Partier, and GCN games are only set up to use one anyway. And Odama's coming with ANOTHER one, right? What are you supposed to do with all the mics if you actually want to buy these games for yourself? Donate them to friends who don't have the games that use them? Not like EB or any place will give you anything worth bringing them in.