NCM for Windows and VMware brings some performance benefits which mostly reside on network routing and path selection; in 1.4.x we create a series of manual, hard-connected links between each server NIC to each array NIC (ie 2x NICs, 4x Array NICs = 8 manual paths). There is no intelligence about how data is routed down the paths nor is there any intelligence if a path fails, or has outstanding queues from the network which may be driving latency.
NCM (both for Windows and VMware) works in tandem with the 2.0.x feature of "Automated Connection" mode (found in the Networking tab of the array GUI), which will create the optimum amount of paths required and will then spin up new paths if required for better performance or lower latency on the network. It will do this on a per volume basis to ensure best performance.
This of course comes into it's own when you have more than a single array in a group/pool, but there are still additional benefits for using it in a single array solution. Not least because it makes volume provisioning & management a LOT easier than using scripts!
Note: NCM for VMware can only be used when the Enterprise or Enterprise Plus licensing is available in the ESXi host, as it's a "feature" restriction from VMware. If there is another license found the install will fail. In this instance, using the scripts we use in 1.4.x is recommended.