I really like MAS9 for its student tracking and management features for my Taekwondo school. The billing system is particularly great as it makes it easy to collect and schedule monthly membership payments. The belt testing system is also a standout because it allows me to create and send or print certificates immediately and share evaluation scores for students. Additionally, the member app is a big plus, as it lets students practice with our curriculum videos, sign up for events, and buy merchandise from home. I also appreciate the awesome customer support and how quickly they update things. The initial setup was pretty easy with their help on data transfer, and I find the features better and more powerful than those of Kicksite and AMS, with a better user experience than Spark.