Top notch addon. I used Speed Dial(fvd) before and I appreciate GSD's fast startup time and intuitive menus with many well thought out settings.
Few feature suggestions:
- option to set the bar with groups to autohide for a more minimalistic look
- option to apply visual settings in Edit group menu to all groups at once
- mouse-over effect for dials where they go from dim to fully bright

Thanks and keep up the good work