VxRail Write Latency - "DOM Client"

Greetings,

I recently started a job where I've inherited a 6-node, all-flash VxRail cluster.  It's all on ESXi 6.5 and the latest VxRail Manager version (4.5.225 I believe). It was just deployed this past summer, so is brand new.  At the moment, there are a number of test systems in the cluster that have been used for validating performance.  Two of these are Windows Server 2016 machines that I built so that I could do some basic testing on my own.

The tests that we're conducting are large file copies between the two servers.  The problem I'm seeing is huge write latency on the "DOM Client" object.  Essentially, the host where the destination server is located is exhibiting high write latency.  This is shown both in esxtop as well as vSphere Web Client (from the destination VM, going to monitor --> performance; both vSAN graphs show the latency).

Now, this latency depends on the storage policy I know.  With FTT1, Stripe 1, I'm consistently seeing 100+ms write latency for the 'DOM Client' object.  When I change to FTT1, Stripe 4, I'm consistently seeing between 25-40ms write latency.

Since there's nothing really running in this environment, I'm a bit surprised by this.  I'm trying to prepare myself for when production VM's enter the environment and a user says "the VM is slow" - how should I interpret that data?  To me it seems a problem (and I do have a ticket open, but nothing concrete has been found so far).  Curious if anyone else has run into anything similar?