What you say about the difference from Pikachu to Ness is true. Pikachu suffers far more from it.
Polygon Ness Vs anyone will have a hard time recovering still because he is slow. He is light so it's easy to throw him off, and gimp him to death, especially with no Third jump variable. Ness's recovery, while predictable, was really helpful for covering distance.
Since NO ONE has a third jump the only chars who wont be getting gimped every time they get thrown off the edge are Kirby Yoshi and Jiggly. The rest of the cast have a fairly equal recovery...which is mostly based on air speed, fall speed, and the priority of the attacks they can use while jumping back (to possible ward a edge guarder) . Ness is slow (easy to defend) and Light (easy to launch).
The rest of the cast how ever also has something to highlight them (except obviously the ones below Ness)
Kirby is obviously tearing everything apart with his smashes and tilts...and also ...he can still recover lol
Yoshi can combo most of the cast very well (the only B move he can really use in a combo was Down B) and has a few strong smashes Usmash, Fsmash, Dsmash, and a Spike.
Fox is still really aggressive and since projectiles cannot be used he is harder to gimp and manipulate. His Usmash while powerful, does not take much advantage of the fact that no one has a third jump.
Pikachu still has powerful Tilts to control the air, and unlike fox has a lot more horizontal knock back attacks. A few Utilts, a Uair, and a Nair and good bye.
Falcon has his Usmash and Uair, to rack up quick damage, while having Bair, Nair, Fsmash, and a spike to help abuse the lack of a third jump.
Jiggly Can combo most of the cast and has some viable finishers in Usmash. Fsmash & Dsmash make better use of the no third jumps though. Her Nair is VERY good for gimping, especially since she can JUMP out to get you! She would be higher imo but her draw backs are too big. Being the lightest char she can still get KOd from low %s, regardless of recovery.
Looking at this i think ima lower fox a bit too, his move set doesn't take advantage of the no jumping as much as i first thought
EDITED IMO~
EDITED IMO~
Kirby (Jumps, finishers and combos)
Yoshi (Combos, finishers, super armor jump)
Pikachu (Combos, finishers, fast)
Falcon (Combos, heavy weight, fast)
Fox (Combos, fast, heavy weight)
Jiggly (Combos, jumps)
Ness (Combos, Finishers)
Mario (Combos, mid weight )
Link (Combos, Heavy weight)
DK (Finishers, Heavy weight)
Samus (Mid weight)
Luigi (Mid weight)
Legend:
Combos - The char can do decent combos with only normal attacks
Jumps - The char has extra jumps without the use of special attacks
Finishers - The char can kill a foe easily (Spikes, strong smashes, easy gimps ...etc)
Fast - The Char is quick (since no one has projectiles this becomes more important imo)
Heavy weight - the char is harder to finish (due to the lack of a third jump this becomes slightly more important then normal imo)
Mid weight - The char is harder to combo
Super Armor Jump - The frames Yoshi gets in his jump where he cannot suffer knock back (Which gives him one of the best recovery's for a polygon)