We run a lot of ESXi with vSphere (part of overall VCF solution). It works very well. But I am part of Big Corp. so they don’t mind paying. We are good via warranties etc using what we already purchased. I don’t know that I share the same sentiment that we could have just used ProxMox. We are a Dell heavy shop and there is a new Dell Private Cloud product that is very promising. More like choose your own adventure.
Dell private cloud lock in would be the death of any company. You don't want to be isolated to one hardware vendor. We've told Dell to kick rocks many times for renewals and would not be able to do that if we were in their Cloud, which requires Dell hardware. Don't do it
It’s on prem