Hello,
The full list of Pro features can be found here:
https://github.com/fastaddons/GroupSpeedDial/wiki/PRO-version-features
But I would say all basic features should be there. My addon didn't have any Pro features for a first few years, I've stared adding them only much later on.
Feel free to contact me to my support email if you have troubles setting it up, I know some things are not as intuitive as it should be. I'm working on those now...
Best regards,
Juraj Mäsiar