Yes! I don't say bird better frr. I mean when BFD is needed noc choose bird, because *quagga* doe's not support this. Frr does not have to go the same way! At the moment, the product is just gaining popularity, so if a road map is available (Donald created frr 2.0 -> frr 3.0 on github and is good), then in the long term the first acquaintance will be decisive in most cases, I think.

Frr looks good because of the vrf, mpls, and l2 advertisement tie-ins.  So I'm not sure if bird is a suitable substitute for this.  I havn't looked at their feature set in a while.