I've been a customer (on personal account, not professional), and will never come back.
I had "ghost vms" being billed that I had deleted, but openstack would keep them in "deleting" state for months (or something similar). They were just one short test for an hour and I've been billed over 1200€ in 4 months. The only way I got a (partial, 66%) refund was having some indirect connection to a VP there. If it wasn't for that I would either still be billed while talking to robots on their ticketing system, or been blacklisted and my account sold to some sort of debt
recovery company and it would be a legal battle (which their bots threatened).
Aside for that, I had interviewed with them before, and they are ultra-arrogant smart asses, asking you details on the linux kernel for a 40k/year support role.