I agree that it's very difficult to compare modern stars (Bonds) to those of an older era except in the way that they compared to their respective competition. So Babe Ruth drank a lot and was overweight, but he was still head and shoulders above almost all players at his time. There is no way to tell how he would fare today hitting off of Roger Clemens or Jonathan Papelbon. There is also no way to tell how many bombs he would have dropped if on hGH.

But Bonds' 14 All Star selections, about half dozen MVPs and lifetime slugging% around .600, etc. is hard to argue with (lots of them from when he was the twig seen on the left side of that photo).