I like that they are very proactive when it comes to their customers needs and wants! They have helped me with several issues over the years and always responded quickly and effectively.
The only thing that I dislike about them is that there sometimes seems to be communication gaps between departments (accounting vs customer service). That being said, this can usually be resolved by contacting one of our account managers who will get back to you right away. We've been using conservice for almost 8 years now - we were looking at other options but after trying out so many others realized how great conservice was.