Business Computing World published a review of Red Hat Enterprise Linux 6

There's little doubting that this new release of RHEL is a worthwhile investment, enabling customers to take full advantage of the latest multi-core hardware with the promise of even greater scalability in the future. New buyers and those deploying new servers should certainly have no hesitation in choosing RHEL 6 to host their Linux applications. Whether it's worth rushing out and upgrading existing systems is less clear cut. Especially, for customers with large numbers of Xen virtual machines who may prefer to wait a while before going through the pain of migrating to the new KVM technology in this release.

  Red Hat Enterprise Linux 6 Review