The user interface, ability to schedule appointments in advance without having to look up an address or phone number, and that is can be accessed from anywhere with internet access. It would be nice if there was some way of seeing who has viewed your appointment before you get into it. I use ibis scheduler for all my appointments at work because it makes scheduling a breeze! There are no downsides, but like any other software program out there, there may be things we don't know about yet which could improve its functionality. If you're looking for one-stop shop scheduling solution that provides reliable service and seamless customer experience, ibis should definitely be considered as part of the package. We have used this product for over 10 years now, and our customers love using it too. We've never had any problems with the scheduled meetings not being attended by their assigned contact person.