Falco takes heaps of practice.
I don't know if its just me but I used to play him (even just a few days ago) and all my fights were quite even against most of the characters.
But now I've been hopping into training mode. And practicing my chain grabs and overall my spiking techniques and then firefoxing back into the stage. I've also practiced dropping off the stage, one jump (facing in opposite direction to opponent) and then bairing them around. I also practiced against a running away cpu and a continuous jumping cpu. Although I already did these things, I didn't do them well. And just two hours or so, maybe more (in the last 24 hrs) not only have I learnt many new things (well upgrades of things I already knew) I seem to be better at knowing what to do in situations, my reflexes are better (with Falco) and I'm just playing better. Training mode really makes things come together. And rather than practicing in Group-Brawl all the time I'll spend majority of my time in Training mode.
In fact, I used to just concentrate on my ground game, getting heaps of rolls in, grabs (chain), AAAs a couple of shorthops + fair here and there (which werent really beneficial because I just realised they only land 2% most of the time against a good opponent). But now, as my game is coming together, I'm shorthopping and bairing, dairing much more precisely and something really good also happened - I've picked up the technique of fsmashing beautifully. Almost all my FSmashes work, especially around rolls, pretty much whenever I can punish and after AAAs too (sometimes with a shorthop first). I've also realised that when my opponent is on high % and they are really coming at me aggressively, and I want to space them, I use shine to do it. Everyone knows this is a good technique, yeah? But a good thing to note, if you dont already, is that a lot of the time the shine TRIPS your opponent. A quick little run and one FSmash can send your opponent flying out of the stage.
Mastering Falco will take a long time, but to become a good Falco, people need to use all his techniques. They need to be good in the air, knowing went to use his dairs, bairs uairs, know how to chain grab very good know how to edge-guard, ledge-guard well and you know, all the other stuff I mentioned. Everything has to come together in the one game and I realise its a lot. I really think that Falco hasnt been too successful yet because when people get into the mood of being very aerial they eventually become very easy to beat as the opponent gets used to their next move. People have to get into the habit of using everything he has, and in every situation, the best techniques for the job.