I ran OpenBGPD about 15 yrs back for peering access to a Metropolitan Area Network. My first/last/only experience with BGP (thankfully hehe).

OpenBGPD itself was solid and looked at lot easier to configure than the alternatives. Can't remember whether I looked at Zebra or Quagga or both though.

Haven't used OpenBSD itself since those days either, but OpenBSD originated software tends to have that straightforwardness I miss sometimes.