I can do over 270Mbps down and 80Mbps up (May be limited by my upload, download is a CPU limitation) on a RBM33G as a client-router.
I'm not 100%, but it may actually be 370Mbps down, but I don't want to advertise that number without being sure. I replaced it with a RPi4 as a router-on-a-stick WG gateway. The RPi4 has no problem keeping up with my 500/100 fiber connection.
The RBM33G has a pretty weak MTK7621a dual core 800mhz MIPS cpu.
I should setup two of them and run some proper benchmarks at some point.
You'd be surprised; I'm pulling 150Mbps on a years-old $40 Edgerouter X (it was on sale when I bought it; it's normally $60) over Wireguard to Mullvad.