So, not to brag but just to set the context, I was considered "the best Jiggs" for the first few years of Brawl's life. I won quite a few sub-regional tourneys with her, and placed pretty decently at regional events in spite of, well, playing a somewhat awful character.
Jiggs is overall a better character in Smash 4, but a few things keep me from playing her much:
The big one is Pound. Pound was Jigglypuff's trump card in virtually all bad matchups. "Thinkaman's Law of Brawl Jigglypuff" was "The worse the matchup is, the higher percentage of your actions should be Pound." Jigglypuff had essentially unmatched spacing capabilities, but poor range and speed. (Similar to Wario.) Characters who offered fast disjointedness could just wall attacks and consistently shut down everything about her plan--until Pound comes in.
Pound said "screw that noise" and just flat out won against pretty much anything but a G&W bair. Sure, it was a high-risk move with certain punish on whiff, but against mindless walls of attacks it was a safe bet. What was critical, was that the momentum of Pound let it be used comfortably early and enabled it to beat purely defensive walling that wasn't even going to hit you. Meta-Knight's poor aerial mobility in particular was harshly punished by Pound; Pound turned an otherwise disastrous matchup into a shockingly okay one. It was also crucial against the dominating disjointed ground attacks of Snake.
Smash 4 gutted that momentum from Pound, leaving Jigglypuff--while otherwise a much better character--without a trump card to save her in problematic matchups. If it weren't for massive (and highly justified) nerfs to the extent of fast disjointedness in the game, she would have a few hard counters.
The next issue is speed. In Smash 4, having fast attacks matters. A lot. Literally all the characters we consider candidates for top tier have fast attacks. Jigglypuff's moveset, both ground and aerial, is very slow. She relies on her unmatched mobility instead, but in Smash 4's environment this isn't as good of a plan.
Next, the proliferation of vertical kills in the environment. Brawl has Shuttle Loop and Snake u-tilt. Smash 4 has... basically everything. Diddy uair, Rosalina u-smash and uair, ZSS up-b and uair, Sonic u-smash, Ness uair (and sort of b-throw), Pikachu u-smash, Fox u-smash, Falcon uair and side-b, Yoshi u-smash and uair... It seems like all the scariest kill moves are vertically-focused, and Jiggs is terrified of this world.
Jigglypuff's Grab seems a little smaller, and her great dash grab is much worse. I played Jigglypuff as a roll- heavy grappler on the ground, and this doesn't pay off as much in this game. I also used DACUS as a good mixup for this playstyle, but that's gone too. (No complaints though; DACUS was a stupid input)
Then we've got Rollout. Rollout was like the Little Mac of Brawl. It was by no means good, it only worked well on certain stages, and using it foolishly, including in neutral
ever, was a death sentence. But like Little Mac, it was grossly underrated and dismissed entirely by players who didn't understand it. Rollout was a reliable KO-capable tech chase in highly specific situations, and a surprisingly threatening recovery option in certain matchups. (The overlooked key is that you could release at a very wide variety of heights. In most matchups, at least one of these heights ends up being safe for any possible opponent action.) Very frequently, the slightest differences in release timing on aerial rollout could beat attacks meant to punish other timings. (This was less and less true the more range the opponent had.)
In Smash 4, Rollout is just as unsafe but a lot weaker. What's more, the aerial version bounces off shields instead of going through them safely. This means that the range of valid recovery paths is cut short a small but critical amount--the opponent no longer has to correct place an sufficiently ranged and timed attack on the air-to-ground paths, just be in the way and shield.
The Rest buffs are fine, but some vertical KOs in this game are instant. So... I guess I'm actually not allowed to use Rest except last stock? So much for that I guess.
Then we've got the new air dodge landing lag. I feel that this slightly hurts Jiggs, overall. In Brawl, her mobility and last hitboxes on nair and Pound gave her unique ability to punish landing air dodges anyway. On the other hand, Jigglypuff could convert her aerial footsies into a ground grab with a "triangle jump" sort of approach, which would beat many defensive moves meant to beat her unusual air game approach. Now this transitional option is removed.
Finally, while Jigglypuff is buffed overall from it, I'm uneasy about putting all the character's power on bair. What about matchups where landing bair is hard? As discussed earlier, used to this is where Pound came in, but it's a lot less reliable as a back-up plan now...
Oh, a bonus "nerf" that's just ironic. Jigglypuff used to have a 7:3 matchup against Diddy in Brawl! This was because she could consistently Rest him out of dash attack, jab, f-smash, and u-smash on reaction, which all had one-frame gaps in them. These were fixed by changes to Diddy. (Note that if they were not changed, Little Mac would also be able to up-b all these things on reaction too!)
I am conflicted. New Jigglypuff feels like an already poor character who was modestly nerfed and put in a more hostile environment. On the other hand, she was compensated with:
- One of the most legitimately absurd hitboxes in the game put on her primary move, bair.
- A reasonably scary, frame-1-invincible, frame-1-hitting KO move in a game that places an emphasis on speed and pseudo-combos.
- Massive nerfs across the board to fast disjoint, which was her biggest problem. (G&W and Marth were hard counters in Brawl.)
So if any of you from the old days were wondering why Thinkaman isn't just beating everyone with buffed Jiggs, there's your answer. Maybe I'm just resisting change and need to just put in the time, but she's... just so weird to me.