The whole flight controller firmware landscape has changed dramatically in the last couple of years since the introduction of the Naze board for FPV racers running baseflight firmware.
As opposed to software (r)evolutions, flight controllers hardware did not evolve as much (apart from processing power increase, nothing revolutionnary). One noticeable novelty on hardware level is the relatively new open source "SP racing F3" board. Made a quick tech review of this board in the video which, as I understand it, became the state of the art flight controller for "seriously pro" FPV racers.
This video also shares some brief historical & evolution about hardware/firmware for FPV racing (MultiiWii evolution branch).