Yeah it still does its job if you get it off, but the first thing I did when deciding to pick up Falco on this game was just pretend like it didn't exist anymore. Its hitbox is in no way forgiving, it's very slow, has little range and its landing lag is horrible.Dair is like a surprise move, so you can't use it a lot and you need to have good damn read. Once it lands and you meteor someone it's so satisfying. Same with on stage e.g. meteor someone back to the ground to give yourself a breather or something.
I'm trying to slowly put it back into my arsenal, but i've had 10x more success with illusion spikes than his Dair. It's still a great card to keep hidden though.