I'm using ffmpeg on Windows to create mp4 files for web distribution. As libfaac isn't available, I use libmp3lame to encode the audio tracks. The mp4 are played back with a falsh player (JWPlayer)
I was wondering if there were any shortcomings to use mp3 instead of aac on certain devices?
If JWPlayer can handle it, it's fine. MP3 is a more open and portable format to begin with.