My take on ovirt is that it is focusing on (moderately) large-scale deployment, albeit only really covering the hypervisor aspect of things , whereas openstack seems to have a broader focus.

I recently evaluated ovirt in a small business context, and one of the stumbling blocks was, "how do I specify which VMs should be automatically run at boot time, and how do I control the order in which they boot?" The current answer to that with ovirt is in effect: "Well, we expect you to have a highly-availble bunch of management nodes which will simply remember what the set of currently running VMs ought to be. If that doesn't float your boat, maybe you should use the API and roll your own control system."

From a small business context this basically amounts to: No.

Note that this is not a serious criticism of ovirt. A project has finite resource, there's only so many things they can focus on at one time, I fully expect that things will improve over time, and the stuff that is there installs and runs very smoothly.

I think of it this way: oVirt is an open source equivalent of VMware vSphere, while OpenStack et al are clones of AWS. The former's less complex, but what most "small" businesses actually need.

I just had local proponents here push OpenStack because they thought it was "cool" to have "cloud-grade" virtualization. It ended up being a pain to deal with and is now being scrapped.