We host IP Street’s SAAS product at Rackspace. We’re finally taking the plunge and upgrading from python-cloudfiles to pyrax. We didn’t have any big issues with python-cloudfiles, but I was tiring of getting the brush-off from Rackspace when we asked for help with an API failure.
The benefits of keeping a technology up-to-date far outweighs the costs, unless you’re in an extreme corner case with a very unreliable vendor. Better performance, bug fixes, better capabilities, better support… all good stuff.