I tend to ignore righty/lefty except when looking at platoon hitters in deep leagues. In those very deep leagues, you are forced to take marginal players, and platoon hitters are valuable because they at least produce something. In those cases, I prefer lefty platoon guys because it seems to me they get more at bats. I never checked stats to back that up, but it seems intuitive.
There are a few things with the New York Yankees that never change. That's pride, tradition, and most of all, we have the greatest fans in the world. -Derek Jeter, 9/21/08 -- last words from old Yankee Stadium