I use RoundTable all day every day. It seems to serve its purpose (versioning files and managing change sets) quite well. Like anything else, there are a few things about it that are annoying, but overall, it's good. If I were starting my own P4GL software organization, I would buy it.
Disclaimer: we are stuck, seemingly forever, on 9.1D which is a bit dated now. The newer version is fundamentally the same but seems nicer in a lot of ways (slicker UI, ability to run AppServer, some other stuff I forget). Also, I have not seriously used "real" source control products (CVS, etc.) so my ability to judge RoundTable is limited.
