They are good bounty managers and I can say that statement as Yahoo, Sylon and Needmoney are my most favorite as most of my accounts are participating the bounty campaigns under their management.
Yahoo is one has the most successful bounty campaigns as most of them are really listed on coinmarketcap.com right after the ICO sale ends.
Sylon and Needmoney although most of their bounty campaigns aren't paying bounty tokens to their bounty campaign participants but some of their bounty campaigns were indeed successful.