I use my EspressoBin as a router and it does a great job of it. It handles DHCP, DNS and firewalling for my network across multiple VLANs. Initially I tried using Arch Linux and Armbian, which had support for the board at the time, but I had various issues with those and eventually whipped up my own Devuan image. It has been quite stable for me across several releases (ascii->beowulf->chimaera). I do however, still use the kernel package from Armbian's repo.
My plan is to leave some notes here on some various things I've done with the EspressoBin since setting it up as my router here at work.