Taken from our VMWare BPG - avaialbe on InfoSight BPG page:
Storage IO Control (SIOC)
Storage IO Control (SIOC) enables QoS (Quality of Service) for shared storage access between virtual machines. It is purpose built to address the “noisy neighbor” problem that is common in shared services environments. One can define shares and IOPS limits on a per virtual machine VMDK level, to ensure critical virtual machines are treated as first class citizen.
Nimble Storage Consideration:
No additional configuration is needed on the Nimble array side to take advantage of this feature. Simply set higher share values and IOPS limits for mission critical virtual machines, and the I/O QoS enforcement would work accordingly.
So feel free to use it on a per VM basis if you feel it is required.