The ease of use, how easy it is to view my schedule for upcoming appointments in real time so I can be prepared when an appointment comes up! It's also great that you don't need any special equipment or software - just log into their website from anywhere with internet access- even if its only through mobile data (like using wifi hotspots). Sometimes there are minor glitches but they quickly get resolved by contacting customer support via email/phone calls etc which takes care off issues veryβ¦