Virtualization products comparisons are almost common, but usually are too much (single) vendor oriented and each try to bring better conclusion on its products. So it’s difficult find something that it’s really independent. Also customer experiences could be polarized by their knowledge and the experience itself, or (and this could be worst) by a better design or architecture choice. I’ve write something one year ago (see this post), but of course products change so things also change. So part is still valid and part must be updated.