This chapter was an overview of virtualization technology from a vendor-neutral perspective. There is always the question of which virtualization software is best. There is no single correct answer to this question unless it is either emotionally based or prejudicial in some way.
All virtualization software does the same thing: virtualize physical machines and the services that they provide. You'll have to decide what you need from virtualization and then choose the best technology that fits that need—and worry about vendor specifics later. You may also use more than one virtualization solution to solve the various needs within your network.
If you're going to invest thousands, perhaps hundreds of thousands, in virtualization, you need to experience the software for yourself. Vendors know this and are willing to work with you. Many offer full versions for a trial period. If a trial version won't work for you, get in touch with the vendor and get the actual licensed software for evaluation.