For what it's worth on deciphering the PED thing, my view is that you try and discount that part of their career (to the best of your ability). If there's strong evidence of steroids, you exclude cases on the bubble. You never exclude on the basis of strong slugger with a big head and you have to keep in mind that pitchers are probably just as likely if not more likely to have benefited. However, marginal players who got better late in their career with ties to steroids around the same time period should be treated as marginal players and not Hall of Famers.
Given these statistics, there's not a doubt in my mind Barry Bonds should be in since he would be deserving even if he had a career ending injury the day before he used steroids. However, someone like Mark McGwire doesn't have much going for him besides homeruns so he's always more marginal and his most noteworthy time period was one he clearly was using steroids. So he probably shouldn't make it.