I have been able to connect with my Google Calendar and the "Test Connection" link successfully updated the calendar at the Google end. However, syncing the other way does not appear to be working. I updated my calendar in Google to block off a spot of time and the changes are not being reflected in the Appointments+ web page. These time slots are still being shown as available.
I've double checked and the Integration Mode drop down menu is set to A+ <-> GCal (Synchronization). So I'm not sure why two way sync is not working.