I like that it's easy to use with all of my clients in one place! It has made communicating so much easier than having multiple different emails scattered about from each client.
There could be more features but this isn't really an issue as long as you're willing to spend some time learning how everything works - which won't take too long at all once they've been explained properly by our support team (who are always very helpful!). We have used other tools before where we had to create individual accounts just for certain people who needed access to specific information or files; however, since using TopicBox, everyone can easily see what others do within their own account without creating separate ones themselves.