As a starting stage? It doesnt really fit the bill of relative neutrality among characters. In the first transition, you have two things to watch out for; a temporary wall and a ledge impossible to grab. You obviously can't infinite on the wall because the platform rises, but G&W's Dtilt can certainly rack up a good deal of damage and hit with a finisher in the time for it to go make to the middle position. When it's up, its incredibly hard for characters to recover. You cant grab the edge, so you must land on ground, or on the upper platform, meaning it's incredibly easy to ledgeguard. Also, it's a very bad situation for characters with only tether recoveries.
The transition is also a problem. It puts many people in an awkward position, whether they end up under the stage or far out to the sides. Oh, and this scatters all of Olimar's pikmin, making this transition almost like a free stock.
The second part isnt so bad, and the only real issue I see with this might be the moving platforms off stage. If you use a get up attack or roll on this and it pulls offscreen, you're dead. If an opponent grabs you and already has the stock advantage, he can easily carry you off with himself.
So all in all, it's a great counterpick, one of my favorites, but it doesnt seem to be a quality neutral stage.