We are looking for a tool (or set of tools) that will assist us in an AD 2003 to AD 2012 migration. The tool needs to automate the synchronization of accounts, groups, attributes, SID history, passwords, etc. from our old AD 2003 Forest to our new AD 2012 Forest, and the synchronization of some attributes back from AD 2012 to AD 2003. This migration project will likely take 2+ years, so we will need to maintain both AD environments synchronized in some manner during that time. We have 60,000+ users currently in the AD 2003 Forest across 20+ different domains. The new AD 2012 Forest consists of the root and 2 child domains, with all users going in one of the child domains. There will need to be specific mapping from the old AD 2003 Domains/OUs to the new AD 2012 OUs. Ideally, the synchronization would be triggered by a change in either Forest, or as an alternative, could be scheduled to run a few times per day. We have looked extensively at Quest One Quick Connect, but we are having some "challenges" getting it to work in this complex environment. FYI: Quest Migration Manager for Exchange will be used for the parallel migration from Exchange 2003 to Exchange 2010.
Anyone have any ideas on other tools that might fit the bill for a complex AD Migration/Synchronization? Actual migration experience with the tool would be a plus.