It really depends on the race distance you plan on using them for. In the application of "Aero" and long distance (ie. Ironman distance with a simple out and back like in Kona), I like the HED bar with it's integrated brake levers, and have it on my long course bike (claimed 800 grams). My #2 choice for this type of application would be the Vision Tech TRIMAXCARBON zero degree flat wing, it is a combination of my long course choice and my short course choice, at 850 grams it's not bad (not including stem or brake levers). This bas gives you a positive place to grip the bar "cowhorn" style - there is really nothing on the HED to grip except the ends of the wing - not the greatest comfort - bust as I noted for long course you don't care as teh aero pocition is where you are mostly and it's the most aero product out there. Many of my friends use the HED bar for Time Trail specific applications. I'm a big fan of the integrated one piece carbon bars.
http://www.hedcycling.com/cart/aerobars.htm
http://www.visiontechusa.com/fly.asp...xid=84&pid=130
For something shorter that has many course changes you need to have a hand position that improves your bike handling (the cow horn position) - for this I like the Profile Carbon and I have this on my short course bike. But again - this is total a personal choice.
Easton attack would be my last choice after everything else.
http://www.bikesportmichigan.com/reviews/barwars.shtml