Picochat:
I love Picochat but I have a hard time seeing people agree with it.
Half the transformations allow Dedede to wall chainthrow.
Nearly all promote camping to a degree.
No warning of change unlike PS1 (the screen in the back)
Cart and Spear points can kill. (avoidable) bullets and the fire are minor annoyances although the fire might make for some cool combos =D
Great Sea:
Nothing wrong with this stage as a counter pick at all.
Flicker- as Darrel said DI it. It covers a TINY area its not like the entire boat flicks you off and it's always at the same spot. Or avoid the spot for 5 seconds...
Bombs- They shoot in 3 general spots left, right, middle if you just pay attention to the trajectory all you have to do is jump or roll or run out of that spot. The bombs take enough time getting there for you to avoid it.
Storm- lasts for 10 seconds about. On the way up can leave people behind if they are stupid and stay in the water. About 5 seconds of low gravity.... can't really complain about that.
Only thing wrong with the stage is when it hits the rock. Giving a wall for Dedede or fox. Also can get campy one person on the rock, other on the ship
I don't like distant planet no reason just personal preference. =)
edit:
Just read Dguys post gonna give opinions on some of the stages he listed.
PS2.
Wind level- If you're in the air it's too hard to get back down. Any one decent should be able to keep you in the air for a while. Since jumping is slower and punishable air game dependant characters will suffer. Example I can't short hop bair approach with Dedede he just floats over smaller characters and I get hit out of it all the time.
Treadmill level-Slow characters have a hard time getting off the edge. Get up, fall right back down. The only way to get off the edge is jumping. Reducing their options on the ledge. Which might lead them to just stall on the edge. Basically get big slow characters on the edge and if they try to get up it a free hit.
Ice Level-Other than the sliding around nothing really wrong with it. But the sliding makes it difficult to control your character.
Fun note: If you try run and turn around your character will stay stuck in the run turnaround animation all the way across stadium looks funny with Dedede. You can't shield or attack but you can jump out of it.
Also I heard Ice Climbers don't slide on ice.
Dirt level- Fairest of the 4 until you realize the mound in the middle is a wall =D I don't know if the left side is a wall but the right side is.
Am I missing a transformation?
So that's 1 good form(default) 2 Bad and 2 Decent in my opinion. I'd like to not play on it
Hanenbow-
Platform moving disrupts combos at times (we know how hard those are to get in brawl)
Platform set at the top and bottom left promotes camping.
I've heard Grappel recoveries gets confused on that stage not all the time but there is a chance. (could someone confirm?) If true then alot of the cast have their recovery options limited and in the case of olimar and Ivysaur they have no recovery. The water won't even save them.
It's too noisy.
Not really a location big enough for actual fighting. 2 hits and you run out of floor room.
Norfair-
Alright stage on its own. But the stages gimmicks are too frequent and dominating.
Lava walls makes half the stage unplayable.
Lava spurts sections off a quarter of the stage. Hard to see where it is hitting. Disrupts gameplay.
Lava Rising- Only top plaforms playable too far a distance between the two platforms.
Lava wave CAN be shielded, rolled, sidesteped, and air dodged. But it forces everyone to stop playing to be defensive.
Ledges promote stalling. Grab top ledge. Drop to lower one. UpB back to top and repeat.
Good stage but too many disruptions for competitive gameplay.