Last week I did some Swing2JavaFX Live Coding on the WJAX in Munich (Details). Therefore I migrated a random Swing client from GitHub partially to JavaFX. I created a fork and a screencast (German), which gives you an impression, which technical opportunities you have, if you migrate Swing to JavaFX.
I also pointed some hurdles and showed workarounds for existing problems if you migrate from Swing to JavaFX.
GitHub – Fork of the Swing client
https://github.com/sialcasa/Swing2JavaFXHacking
Screencast Swing2JavaFX Live Coding