The amount of features is great.
My favourites are Payment Processing, SMTP Email, Facebook Client booking, Cal sync and Rewards and Referrals. It has so many features but these exactly what i was looking for in a booking system.
I have to give a thumbs up to the "live" support, they helped me fix a few issues I ran into while integratinh the calendar on my WordPress page. Most places have "email" support and it sucks balls waiting for a reply. Really great support staff who knew their service well.
The "i" info button next to most options is fantastic, a real time saver. Review collected by and hosted on G2.com.