Actually, at the end of the day, it's about the music. Taking physics into mind, and under the right instruction, the 'tilt' has been known to yeild great accomplishments if the 'traditional' is your grip of choice. But, if how they look is more important to you than how they sound, then perhaps you are more the 'visual designer'-type, and not as much of a musician as you might have previously thought. If you would like to know more about my thoughts on the traditional grip, you can PM me.
And for those that think the 'tilt' could affect the 'consistency' of the line, I say:
Consistency will never exist. Always, you are either getting better, or getting worse...
-Austin Osterhout