This is the favorite question of everyone here, I know.
However, I'm going to try and make this as easy as possible by posting ALL the HCIBench results and host them on a site so you can review just like you ran the tests yourself.
My concern is that this 4 node vSAN is under performing, and by quite a bit!
I just cannot detect why it feels slow, but I'm seeing "okay" numbers in HCIBench (sometimes).
I am able to change everything on the networking side since I have two kinds of 10GB switches to choose from, and I have about 8 of each.
The deep-dive data as generated by HCIBench is linked >> HERE <<
I will also post some screenshots of the last EasyRun I performed and viewed through Graphana...
(The build of my 4 node lab is found at the bottom of this post)
Full size versions of these images below can be found >> HERE <<
Below is my setup as HCIBench inventoried it.