I have had Rackspace cloud sites for almost a year now and it works very well for most client sites. However, I am very disappointed that they needed to support .NET 4.0 for so long, and forget about it if you want to use something that requires something beyond average trust. I have not found a single document database that will work yet, and when I ask them about it, the general answer that they would like to give is "Upgrade to the cloud server." This is almost the same as they give you the minimum minimum in the Sites option, and then when something is not supported, they revive you.
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