our DC are VMs and we back them up using Avamar/Data Domain. SRDF will not give you any retention, it is really good at replicating data, including data corruption.
I'm not quite sure this answer's our question. We are trying to determine if using AD controllers that are replicated via SRDF from a production site to a DR site (using the same IP address space) is supported, or if there are any liabilities with using this technique. This is in support of a full data center swing from the failed site to the Disaster Recovery site.
SRDF does not care what you replicate, how you handle DC recovery is an application questions. If you split SRDF and trying to bring up that DC (assuming physical), it will be in a crash consistent state. Same state if you were to pull power cords on a running server.