How good is the Pirates' minor league system?

Before I get into this post, I want to take a second to highly recommend Pirates Prospects' 2012 Prospect Guide. The 2011 version was invaluable to me when I was in Bradenton last spring and throughout the year as I tried to keep up with the Pirates' minor league system. The 2012 book is every bit as comprehensive. I can't imagine anyone anywhere knows more about the Pirates' minor leaguers than Tim and his staff, and the fact that this book is produced by an independent blog is awesome. If you're interested in the Pirates' minor league system at all, it's worth your $20. John Sickels released his minor league organizational rankings today and he put the Pirates' 12th. Even though he did it with the caveat that it's not something he's done before and that he's a bit uncomfortable splitting hairs between every single team, it's a good jumping off point to discuss the state of the Pirates' system as the beginning of the 2012 season d...