Easton's Attack TT one piece, carbon aero bar is the lightest on the market.  It is also drop dead gorgeous and instantly turns your tri bike into a head turner.  The best thing about the bar is its light weight which allows your tri bike's weight distribution to remain relatively balanced from front to rear.  The worst thing about it is the discomfort.  Easton claims the bar is "very comfortable" due to "adjustable elbow pads on shock-absorbing carbon cantilevers (that) smooth out the road and alleviate fatigue."  Nothing could be further from reality; the elbow pads are the least comfortable of any bar I've used.  I think the problem with the elbow pad is two-fold: (1) the thick carbon material does not flex like thin aluminum pad holders made by companies like Profile Design; and (2) the pads are two small, don't fit under your elbow but under your forearm and the grooves in the pad are not well thought out (definitely use the smooth pads). 

If you buy this bar, be prepared to reduce the length of your stem at least 2 - 4 cm because of the location of the elbow pads.  Instead of being elevated above and positioned in front of the base bar, the Attack TT's pads are very low and directly on top of the base bar.  Nevertheless, this bar is astonishingly light, aerodynamic and beautiful and could be much more functional with a few modifications.  Easton should provide a variety of pad mounting options allowing you to move it closer to your elbow and/or higher, change the pad holders from carbon to aluminum and make them much larger.  With these modifications the Attack TT might be an excellent bar.  In its present form, though, it is only acceptable for those who can handle elbow pad placement much lower, narrower and further away from the saddle than most competitor's models and then only for sprint distances.

KDG