I main falcon but I play cpu since i know barely anyone who plays ssbb as pro, and dont have wifi connection..
I connect the knee more often than others, I play on 5 difficulty teaming with a cpu, and I must admit Im not too bad, but king dedede just owns me even on 5 difficulty.
Falcons priority is so low though, and for some people maybe too fast.
I try to combo a side b, jump and u air to ko for lols, it actually works. But working on a side b and f air (knee) is extra hard.
Currently the only people I lose to with falcon are
Lucas, small and dodges many of falcons kicks, higher priority and quickish attacks
Dedede, I dont know!
Pikachu, same as lucas.
Falco, quick, huge priority (i think), strong, continuous a spam is easy and his hits have.. no lag.
Everyone else just fails to beat me on level 5. Im so good >.>