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
I think the vision base bar/ aerobar integrateds are a great deal if you can find them for around $200 which they can be found for. However, note the sizing issues mentioned in the bikesportsmichigan article. Really though, a set of syntace C2s, sytance stratos and stem will run you about 200 so you might as well go aero. http://www.bestwebbuys.com/bikes/sea...=i-srch-search
Oval is another option, likened because of the option to insert hed s-bends as your extension, they are made by the guy who designed the new hed aerobars but only come in a 42cm width(which wouldn't fly no my 54cm bike). For 180 they're worth a look. http://aebike.com/site/page.cfm?Affi...=30&SKU=HB7001
oh and by the way, I run a Visiontech base bar with a set of vision tech clip ons. I'd say they are much more aero than any other non integrated system by far, I only went this way because the clipons were offered to me cheap and I wasn't sure about sizing.