The screenshot belows show vCenter Operations 5 managing a large environment. It has >2000 powered on VM and >7000 powered off VM, total almost 9500 VM. It spans 4 vCenters, so each of them is averaging 2500 VM. vCenter Operations makes it easy for you to see the health, workload, faults etc at a glance across all these objects. Visually, you can tell which ESXi host is not healthy, or unable to cope, or having faults.