News coming out of the USA is that all new F3’s will have improved dust proofing around the sensor assembly. I have not had a problem myself with either of my F3’s, but I have read of some people that had to have there sensors cleaned or even replaced by Sony due to dust ingress. So, with S-Log getting added as standard and small improvements like this the F3 continues to be a great option for shooting with a super 35mm sensor.