The line is a good place to mount unles you really know where you like your skis to ride at. I did some math and set my stealths 4.5cm back from absollute center. I think the reccommended line is at about 6.5cm back. Remember the closer to center you mount them, the further up you are on the sidecut, and the more work you have to do to turn the ski outside the park. Also, less tip can mean a little less float in powder.
The reson I set mine where I do is for park riding and switch riding/jumping. I like the additional few cm of tail.
It's all up to you, but unless you know how you like your skis, I would mount on the reccommended line.
...he died doing what he loved. He will always be rememberd as a great snowboarder, but more importantly as a great friend.
In loving memory of Josh Malay.