I have used this plugin in a number of environments now. I've used it as a standard calendar booking plugin much like many of the cloud services out there. But I've also used it for a Ghost Tours website where people can RSVP to events (and pay). I also have used it for a local barber shop to handle online schedules.

The SMS messaging and email notifications are all fantastic. Also their support has been responsive the few times I've reached out for help.

The only cons I would say are:

1.) You will need a transactional email service for notifications. Sendgrid or something similar is fine, but just be aware. Its not really a con for this product, in fact I find it a pro since I don't like relying on cloud services. Since we're self-hosting, we have to answer the question of email deliverability ourselves instead of relying on a cloud provider to do that for us.
2.) The settings can be difficult to understand. They have quite a bit of flexibility, but it isn't immediately apparent which settings are where.
3.) The event scheduling management is a bit finicky. Setting up recurring tours on my Ghost Tours website was not the simplest. All recurring events have to have an end date, so I set my date out to 2023 which means people can book a tour in November of next year and it would allow them. It would be simpler if we could set it to recurring with no end-date with a "Don't allow bookings past 90 days" feature which I've seen on other calendars out there.
4.) Recurring events can't seem to cross past midnight. You probably won't have to deal with this, but when you have a Ghost Tour that starts at 11pm and ends at 1am, you will be disappointed that the booking plugin does not allow you to schedule that. So in the plugin the tour ends at Midnight but we were clear in the description to state that it goes longer. Not elegant, but a limitation of the plugin.

But don't let the cons deter you. This plugin has been an excellent addition to my toolkit and I turn to it often. Five tacos from me :).