I've been using WireGuard on my router for the last 6 months, and it's fantastic. I get the full speed of my line through it, when OpenVPN was only giving me 20%. Because of the great plugin they have for Vyatta I'm going to be looking at using it for some stuff at work now too.
The EdgeRouter Lite 3 also happens to be one of the few generally available Mips64 platforms (Cavium OCTEON CN5020). Actually I have just ordered its big brother EdgeRouter Lite 4. It costs double as much, but it also packs a quad-core 1GHz OCTEON CN7130.
By running speed tests through both tunnels. I was getting ~7Mbps over OpenVPN and get ~35Mbps over WireGuard to the same server :)
I believe the speed difference is primarily related to the processing power of my router. WireGuard is seemingly much quicker because it's less intensive on the router.