I used jclouds-cli to get a list of containers that we have on RackSpace cloudfiles-us. This result only returned 10K containers. When I tried this using the swift command line tool, it showed me that there were 10749 containers.
I verified found that some of the more recently created containers were not returned by the contianer-list command.
However, if we already know the name of the container, other commands such as list (list blobs in the container), container-exists, etc. worked correctly.