I think what really impressed me was when we were given an opportunity for them to come in our office during lunch time so that everyone could see it working first hand! Very beneficial - you can't always trust reviews or recommendations from others but this gave us all reassurance of its effectiveness as well (and no-one even knew who made these changes!).
The benefits/opportunities are still ongoing which has been great, however there have not being any significant improvements since then either :) Great product; easy way to integrate team communication channels into one place without having lots more systems running around trying to keep everything together!!