It is effective in presenting a clear layout of the file system when checking in and out files.
This is the bane of my departments existence, almost as universally hated as Satan. At a review session concerning our department, the main issue preventing us from getting our job done was synergy. It is TERRIBLE at going backwards, is TERRIBLE at merging, and is extremely poor at building baselines. Additionally, I have been told it is extremely expensive. Go with a newer software like Git.
Don't use rational synergy
We are using it as a version control system and a configuration management. It does a good enough job to not destroy everything.