Yeah, a rating system would be actually nice. Even though bounty managers are not responsible and cannot influence the actual ICO results and the success, what they certainly can do is to provide a good communication to the bounty hunters. What I have experienced a few times is that sometimes bounty managers would respond with a huge delay (days) to quite important questions or would not respond at all. I know that it must be difficult for them to handle all the requests however communication is one of the most important factors here.