I don't know about the early generations, but the current generations give you the ability to run the shifter cable either in front of, or behind the bar. I ran them behind on mine and it works fine. In essence it gives a little more "platform" for your hands, but not enough to really matter. If anything, set the cables up how you want them, take a short ride before you tape, and if you like it, keep it that way. If not, change it. Some people prefer to run the cables around the front. I probably will next time around.
-Gene-