"Nutanix node you will be running vSphere on top on the underlining Nutanix software" This description is incorrect.Â
There is no "layer" between the hardware and the OS which is ESXI hypervisor on both cases.
Maintenance tasks should be simple with no downtime or no degradation of availability and resources. This is a must for long term hyperconverged infrastructure. The cost-benefit should not grow exponentially, or else the traditional solutions will win the budget planning.