There seems to be some sort of leak or looping problem. After a small bit of usage, Regex Coach becomes unusably slow. Restarting the application fixes this for a short period of time before it must be restarted again, etc.
It would really help to replace all the 10 radio buttons for the group extraction into a listbox or similar UI.
It would also be nice if a better (less bold) font were used, or have the font be user-selectable.
Thanks, Charlie