Sorry.. I was talking about the ROAD attack. I noticed you asked about the SPORT attack. So I don't know anything about the SPORT attack, just the ROAD's.
Since you said you do just alot of straight stuff, I think the ROAD attack would be longer lasting.
Canyon Chasers has a review of both ...
http://www.canyonchasers.net/reviews...oad-attack.php
http://www.canyonchasers.net/reviews...-sport-atk.php
Can't really go wrong with either IMO.
