It has dramatically increased FlightAware’s worldwide ADS-B coverage. The vast majority of ADS-B feeders are Pi-based at the moment (around 11,100 out of the 11,900 currently active) - this includes FlightFeeders.
Try turning off ADS-B and mlat on flightaware.com/adsb/coverage#data-coverage to compare. Some of that ADS-B is not via piaware (e.g. some of Australia, western Europe, China) but the majority is.