Dear Fino,
Here is my single rebuttal, after this I won't argue further because I don't want to be one of those people I was trashing last night.
As for PS2. First of all the ledges aren't the same as PS1, you don't get stuck under them. The only thing you can get stuck under is the stage itself, but that is similar to getting stuck under smashville. I personally think that PS2 makes you jump around certainly no more (in my opinion way less) than other levels such as cruise. No one has qualms with the ground transformation so we just forgo that one.
The ice: all this takes is a little practice on the stage to learn to understand the physics of it. Basically if the move you do moves your character forward or u have momentum while doing a move you will slide. If you have this basic knowledge then you will realize that this transformation really doesn't give any one or two characters an advantage. Just keep your eyes open for sliding smash attacks. There are two platforms that one can hang out on if they feel they are at a disadvantage on the ice.
The belts: there are three platforms on this transformation but really only the one on the left would be safe if someone is in the middle. Strategy on this transformation is to be in the middle, if you can't get there or don't want to be it isn't very hard to plank for the what 30 seconds that the transformation lasts for? What is your opponent going to do in this case? He will slide if he tries to wait for you.
The air: I think that this is the transformation that causes people the most grief but keep in mind everyone moves at the slow speed on this part. It isn't very hard to air camp as a wario would do on any level if you don't feel comfortable fighting in it.
My basic argument is that PS2 only takes a little bit of knowledge and experience before you understand the level and realize that in no way is the level broken. Whereas stages like even cruise give some characters absolute advantage. There is no way any one could argue that metaknight doesn't **** almost everyone on that stage (except maybe game and watch.)
I think the only reason a stage should be banned is if it really makes match-ups unfair (walk-offs, permanent walls to jab lock into, or lets people ABUSE planking <Iowa knows who I am talking about here,*hate*> etc.) and PS2 doesn't fit in that criteria.
That is all. I'm not trying to convince any one here, I'm just explaining myself.