Red Hat Enterprise Linux 7 is more proof that operating systems aren't dead, they're becoming vessels for containerized applications. RHEL 7 performed well in our testing, but it's worth noting that this no longer just a simple OS it's an increasingly abstracted component in the larger Red Hat ecosystem.
Although Red Hat took a long time between the RHEL 6 and 7 releases, during that period they've been sending numerous updates poised towards stable infrastructure.
Another key point -- Red Hat’s virt/virtualization core seems to have taken a back seat to LinuXContainers (LXC), as Red Hat has embraced and financially sponsored Docker containerizing components in a number of ways.
Red Hat has increased support for hosting Windows products in this release. For Red Hat, Microsoft is less of a target and more of a grumbling ally in terms of systems support. Overall support for hosting virtualized Windows Server Editions is less obscure than when we tested RHEL 6.