We currently have exchange 2007 std running in our environment. We've been researching High Availability and we are leaning toward the CA's HA software solution. The other option would be to migrate to Exchange 2010 std and implement DAG. But this would require more time to implement. Has anyone used either or both of the solutions mentioned? What's your opinion on this? I'm kind of thinking just going with CA's software for now and in 3 to 4 years from now, just upgrade to either exchange 2010 or whatever next version might be at that time.