I've been looking at other Appointments plugins and came across Birchpress Scheduler. Looks very similar to Appointments +, perhaps lacking some features.
One big thing that I think Birchpress has over Appointments + is the calendar view in the dashboard that shows all service providers appointments in a really easy to view calendar.
You can also make manual appointments from that view too which is particularly important for walk in custom and follow up appointments.
Is there any chance that Appointments + might features something like this in the future?