Read the data sheet, boasts that you can copy files directly from one ESXi host to another: "Inter-server copy: Copy files directly from ESX to ESX. Files are copied directly from one ESX to another, avoiding the client PC. To allow this, FastSCP sets up a direct data connection between ESX Servers."
However, I'm not sure how this is initiated or if it's just "done" when the source and destination are both ESXi servers that have been added.
Tried copying and pasting a folder from one ESXi host to another, but transfer speed seems underwhelming (16MB/s), although I don't have any base line on this client's network, so it may very well be this slow, but when you're copying 400 GB of data, I'd like to be sure I'm doing it the most efficient way possible obviously.