I disagree on the ^H's. In practice, AWS and SoftLayer spent as much or more time with the 2013 class than the Rackspace people did. I don't know about 2012 though...
San Antonio was never an accidental or incidental choice of venue. It's also not a place where either AWS or SoftLayer has a major presence.
It's also hard not to think of it as TechStars Rackspace when you're in a space sponsored by Rackspace, run by a former Rackspace exec, in a building named for the Rackspace chairman, and in a program administered by a former Rackspace exec. With Rackspace sponsoring, of course.
I work for a company that was in the same class as ZeroVM. I'm not a founder but I was around for the second half of the 2013 program.
Of course Rackspace was involved but Cloud isn't a "powered-by" program like those with Sprint or Nike. Other than ZeroVM, I don't think Rackspace was seriously involved with any of the other companies in the class.
In my experience, Rackspace was pretty hands-off, both with Techstars and Geekdom in general. I think you're trying to insinuate something negative about their involvement when it was only (IMO) positive.
I work on the team at Rackspace that partners with Accelerators IE TechStars. I can tell you there is solid competition from both Amazon and Softlayer at Techstars and we have no extra/special influence in their accelerator.