Nothing so far! It's simple to use, very effective and user friendly with an intuitive interface that makes it easy to learn even if you have no previous experience or knowledge about this kind of software. I highly recommend their services because they offer great customer support. I did not find anything that i disliked at all yet. So far, everything has been smooth sailing. Great job done by them! There are many benefits for using such as better revenue control, more time spent on other aspects than booking/managing guests rooms.