When VMware released vSphere it really raised the bar and further distanced itself from the competition. The performance improvements we will cover in Chapter 7 allow applications that previously may not have been good virtualization candidates because of their intense workloads to now be virtualized. The increased scalability allows for greater density of VMs on hosts, which allows for greater cost savings. Additionally, the power management features can save datacenters a great deal of money in cooling and power expenses. However, although there are many compelling reasons to upgrade to vSphere, there are also some reasons that an upgrade may not be right for you, and we will cover them in Chapter 12.