Easy to schedule, repeat schedule and change bookings.
Easy to adjust and repeat bookings quickly, so once people's appointments are set up it means you don't have to spend time recreating them.
I've used a few club management systems including the big names, and they suck.
Also, it was easy to learn how to use it, and the things you want to do, you can do. Too many club mangement softwares I've used don't let you do what should be seemingly simple tasks around reporting and exporting data for example.
The support and the openes to feature requests. The flexibility of the platform would be the upside for me. I keep learning of better ways to run my business.