I've took the official exam (not the beta one) and this are my comment:
My experience with VCAP5-CIA | vInfrastructure Blog
Note that the time could be a major issue... you have to handle it really well! Better that in DCA.
Also the environmnent is more complete and complex... but not all the systems are required in all tasks.
Finally... you have to wait (more than for DCA) for the result.
But IMHO I found it really good and valuable. After that I suggest to prepare the CID exam, because part of the preparation is the same.