I have been working with them since July 2018 and they've been fantastic! They are always available to answer any questions we may have via Slack or Whatsapp and even when not online their responses can be fast to arrive. Their customer service is first class as well - my clients love dealing with such friendly people who know exactly what they're doing but also don't mind helping you out if needed. Nothing really, they haven't let me down yet and it's only been a few months now so there isn't much to say about that haha. We use them primarily because of our international client base. It makes scheduling appointments easy for us and saves valuable time by having someone else do our admin work instead. For this reason alone they were an obvious choice for us.