Savings? What things do you add up, or forget to add up, to come to that conclusion?

The control is complete, as is the obliteration of your infrastructure and/or your data. Because let's face it, unless you invest the same millions(in money and hours) as Rackspace(or any equivalent company), the odds are against you :)

The knowledge is indeed priceless, if you're into that sort of thing. Some people just need to host their application... reliably.