I have almost always found that meta data does not convert well from one version control solution to another. I always try to leave a readonly copy of the legacy system around for historical browsing if possible.
My focus is usually to port over two or three of the most important baselines and move forward in the new VCS. If you have another experience then by all means drop me a line and tell me about your experience.
Bob Aiello, Technical Editor
For a customer, I have converted CM/synergy to Git based on the project's static revisions respecting the logical history and adding meta-data (baseline, task, objects etc info) to a git tag, so it is searchable.