I will say that a lot of matchup ratings tossed around here are flat-out wrong. The fact is that we don't have any people here that both come on often and play at a respectably high level, and with that in mind we should be focusing more on what we can do in each matchup than giving ratings that are very easily contested.
That being said, Falcon is definitely a good matchup for us. He definitely has some things you have to be wary of, like Uair and Dthrow-> knee (not to mention the stray fsmash/raptor boost), but playing carefully is part of the character and we just have so much going here when done right. The only reliable tools he has to cover where we space our aerials are falling Uair and Nair, which we can bait out or just shield and punish. His oos options are so bad that he basically can't punish our Fair at all (leaving Bair nice and fresh), and we can duck under both of his best approach options. Puff has a naturally good advantageous state that isn't hampered by our usual issues with getting in, and this in conjunction with Falcon's
horrid disadvantaged state allows him very little room to avoid being dragged offstage for an edgeguard, or getting comboed into Rest.
(EDIT: Forgot to mention that Falcon's dash grab also can't usually catch us in the air, adding to the difficulty of landing a grab for him in this matchup. Considering Dthrow-> knee is true on us, that's kind of important.)
also...
@Feelicks, you're kind of overestimating Puff's weaknesses.
-Yes, her options against shield aren't great compared to the rest of the roster, but she still has plenty albeit lesser options she can do to a shielding opponent. Bair is completely safe when used right, Fair is a great mixup that's also safe in certain matchups, fullhop Dair is great on shield in its own right and Pound is a great way to capitalize on weaker shields (you'd think it wouldn't be useful all that often until you realize that one Dair is all it takes to bring a shield to the point where Pound can break it). Even some of her grounded moves are nice on shield, with Utilt being difficult to punish on reaction in general, ftilt having frame advantage and her jab 2 is safe on shield when properly spaced. I'm dead serious on that last one, the thing has no lag and literally outranges all of her tilts. We can also empty hop or SHAD to bait out oos options, and fading Nair is completely safe if you land the sweetspot so it's a nice option when they're right on top of you.
-Going off of her options against shield... Puff's grab game is definitely bad, but it could honestly be much worse and we can still get use out of tomahawking in tandem with our other options. After all, our pummel is one of the most damaging in the game and all of our throws do 10%... for example, a single grab at 80ish% gives us two pummels and a throw, which equals about 16% on them. That's about as much or even more than a number of characters can get off of a throw combo, and plenty won't even be able to use said combos by that point. It also freshens our other moves (including Bair) by three spaces, and we get stage control of our choice without worrying about getting less damage for it. No, it is not a great option and I cannot pretend it will ever be, but that doesn't mean we're completely helpless.
-We have top 9 air acceleration, top 2 airspeed, and multiple jumps to let us turn on a dime. Please explain to me how a character that can cross up a shield thrice with one aerial is in the lower half for air mobility.
-Poor range is something Puff has struggled with since the outset, and Sing and rollout have always been mediocre. I can't deny that both of these issues are exacerbated in this game, though.
-Puff's ground game is actually not as bad as you'd think. Well... no, scratch that, it's pretty bad but that's entirely due to her horrid ground movement. Puff actually has several grounded moves that are quite good, even considering poor range. Our frame 5 Jab is a tad slow for a move of its kind but is still a great way to relieve pressure, can lead into mixups with Rest or Fsmash (Jab->Grounded Rest is true on fatties), can combo into itself and dash attack and has very little commitment to it (also, Jab 2 again has surprising range). Dash Attack is stupid fast (also frame 5), has a great hitbox and priority that's weird in the best of ways. Also, it kills- it's not as good as, say, Meta Knight's and it's generally not too safe but it's just a solid move overall. Utilt is great for combos and cheese kills, ftilt is alright on shield and even her smash attacks aren't too horrid (they all have high startup but to compensate they have low cooldown for smash attacks, Fsmash hits like a truck and Usmash has deceptive range that's also somewhat disjointed. Even Dsmash is alright as a ledge trump option). She can still make good use of all of these by landing when need be, or even just staying on the ground if they're not far away.
Matchups are the one thing that really kills us. Though Puff doesn't actually do too poorly against the cast as a whole, even the top tiers, she still has few advantageous matchups and there are a few characters that could be considered as relatively hard counters (That being said, it's still a better matchup spread than any trash-tier character should be having).
Another major issue of hers is her extremely low tournament representation. This is a problem that feeds off of itself, likely sparked by the mentality of Puff being a trash tier character... as a result, almost nobody wants to pick her up, and the few people who do have basically nothing to go off of in order to improve. Her meta's progression is stifled, and people look at her poor results and are further convinced that the character has no potential. It's a rather annoying vicious cycle.
Personally? I don't think the character is great. I wouldn't even say she's solo viable. That being said, she has enough going for her that putting her near the bottom is unreasonable; my impression of her is somewhere in the confused muddle of fighters that is the middle tier. Even with our issues with representation, new stuff is being found constantly and by this point all it'll take is one person to step up and show the world where we really can stand in the meta.