Unfortunately all cloud solutions are not created equal. There are a number of good cloud and hosting vendors that offer skills and services that differ from Rackspace. Depending on the security, compliance, support and flexibility you need in your solution there are some alternatives that have better services in these areas.
Rackspace is just a tiny part of the rest. Environment, security and reability are the most important points that must be seen together with Rackspace.
I think Rackspace cloud effort around infrastructure as service are just a way to get folks to sign for the private colocation. They do not appear to take LaaS very seriously as they have not implemented Security Groups or VLAN like network that is the most basic security feature one can ask for a public facing hosting. That was at least my experience with them.
Irrespective of any other points, Rackspace's support is pretty awesome and I think that is one area that they truly excel in. I found their products to be great and they do what they say on the tin but - it is the knowledge that should something terrible happen to the webserver or DBs then they have such a fantastic committed team who can solve even the squirliest of issues.
This is my actual experience of Rackspace.