We used Deis at my employer for an internal experiment in having developers easily deploy internal services. This happened ~Feb 2015, so I do understand there may have been sizable improvements.
However; it was outright disaster. From struggling with CoreOS to deis implementation bugs, to SERIOUS bugs in btrfs+docker interactions (>%70 disk usage from metadata) and the docker registry, we ended up wasting ~2 months trying to get it working and eventually just threw it out. I suggest caution when taking on this extremely .. youthful stack of technology.