How to connect XCP-NG to Synology

I will have two XCP-NG boxes with 10Gb nics and two Synology RS boxes with 10Gb nics. I want to use one of the Synology boxes as my VM storage repository and the other I want to use to backup the snapshots and other data.

Which would be the better way to setup the connection between xcp-ng and Synology - NFS or iSCSI/LUN? It seems NFS is the better way but am not able to confirm that holds true when your using it for the VM file itself.

I appreciate the guidance.

They are really close in performance, I would go with NFS.