On the contrary - I think books, especially Kevin's and the Barker's are good guidelines for those without a lot personal experience to go on. As a new breeder, I know that I'd prefer to err on the side of caution, because I don't have the experience that you do under my belt. In the next few years, with more experience and all the "first" hurdles of my first year breeding behind me, I'll feel more comfortable in being able to better read my animals and maybe breed lighter.