Recent years have been a bit disappointing but, as a whole, Dayton has done pretty well.
Draft picks Hosmer, Moustakas, Duffy, Holland, Merrifield have all made significant contributions. As Pete mentioned, guys like Wil Myers, Brandon Finnegan, John Lamb, and Sean Manaea were all promising players who were part of trades that netted big pieces of our WS runs. Throw in the international signings of Salvy, Herrera, Ventura, and that is a pretty nice haul.
Sure, there have been misses and disappointments but from 07-15 Dayton has the fifth-best draft results in the AL in terms of WAR.
https://www.royalsreview.com/2016/6/2/11765574/ten-years-of-dayton-moore-the-drafts