The interface is very easy to use, it's very user friendly. It has all of the features you need for your billing needs. I've never had any problems with water solutions professional. If you are looking for a simple solution to water bill management, this is definitely one of the best out there. There is nothing that i dislike about this software. As far as water solutions professional goes, I have no complaints at all. This software makes my life so much easier when it comes to billing and keeping track of everything. I am able to keep up with all of my bills in one place instead of having to open each one individually.