I am currently using Acuity because it is the only thing that seems to work the way it should for the service business I am running. I would be happy to review how our service business books appointments and sells add-ons right through the Acuity booking system.

Example: Client selects main type of appointment which takes up X amount of time. Depending on the appointment selected, Acuity then presents a bunch of add-ons that are available. If the client selects any of them, it adds Y amount of time to that same appointment based on the selections. The result is one single appointment for the total amount of time with all the order details populating inside of the calendar. The calendar entry must have the location, and a itemized breakdown of services to be rendered (rather than just a package name for example). This is critical to our service business.

One more note - HL would bump it up a notch if you could do address validation and completion on the address they enter for the appointment.

Thanks for your great work!