The team where I work still uses SUN Teamware for Source Code Management (SCM). I've worked with it for a while now (over 10 months) and I don't have any particular complaints about it.
Teamware has been used to manage Sun’s largest source trees, including those for the Solaris operating system and the Java system, and it works pretty well. But it is also an old commercial (closed-source) product that has been discontinued. This came as part of the process of Sun converting their code bases to open source communities which by its turn led to moving to newer revision control systems such as Mercurial.
This makes me feel a bit like we've got stuck in time using Teamware and the world has moved on to newer systems. I do not however miss any particular functionality except maybe having a web view of the source tree to navigate through and see the history of files (something we do with the VersionTool so not critical).
Should a team using SUN Teamware migrate to a SCM more modern like git or Mercurial?
And more important, what arguments can you present to the rest of the team to support that transition?