I’ve recently upgraded our environment from vSphere 6.0 (shush, it’s still in support until March 2020). Fairly standard setup really, a couple of vCenter’s, a couple of PSC’s (to allow ELM), and several hosts. We also ran the HTML 5 Fling as nobody wants to use that god-awful web client which was forced on us for some reason. Yes, it’s been years. No, I’m not over it.
I won’t go in to how to perform the upgrade, that’s well documented and often repeated already, I’ll just point out a couple of things I noticed.