as the adobe support told me, this is known oak bug. So the repository size grows every hour. In my opion AEM6.0 is only usable for testing at the moment, but not for real projects.
Agree it is bug & soon will be addressed. But should not block from going live on real projects. Please ask support engineer to share tool to compact an existing TarMK deployment till hotfix is released. If tool is not acceptable update ticket with business impact & project schedule will help you out.