The practical end result was that you didn't buy "OpenStack", you bought "Mirantis OpenStack" or "Juniper Openstack" (... that one was so broken...) and so on, and there wasn't much portability between them.

The basics worked across all distributions, as far as I know. (The openstack-cli which was built on the HTTP API, which was shared.)

Mostly I had problems with the classic deployment, debug, develop cycle. Reporting bugs is like throwing time out of the window, debugging through overlay networks, über verbose python daemon logs and RabbitMQ madness was also more of a surreally dark exercise in futility, than rewarding experience.

Most of the problems I experienced were problems due to the fundamental trade offs taken during the deveopment of OpenStack. And these are slowly addressed, but ... it was too little too late - at least in our case.