I think the conclusion is that you need to provision a lot of machines, and benchmark your own workload thoroughly to assess any cloud provider. That way you'll have solid performance numbers that are relevant to your case. They (rightly, in my mind), don't come down one way or the other on particular instances or options, because the cost/value analysis depends so specifically on your workload. If you know your workload very well already, they give enough detail that you could reuse some of their data.