I was beating my head against the wall trying to figure out why opening an application through X11 forwarding was taking so long. To open the simplest app like xclock was taking ~20 seconds for the GUI to appear. This was with VcXsrv.
After exhausting ideas on the Linux client, I tried installing Xming on my Windows 10 machine instead and immediately xclock started opening almost instantly (as one would expect).
Could anybody with more experience using these tools suggest why this could be? Or should I just accept that VcXsrv is a POS?