I've recently ridden Pittsburgh-DC in 4 days / 357 miles, and we all used aero bars on our bikes. We all noted a remarkable improvement in our hand conditions vs previous rides without the aero bars. There are caveats - no close proximity to other bikes, no pacelines, not for rough spots/mud - but used in their place, they're ok.

I replaced my handlebar bag with a tri-athlete bag, a mesh thing that hangs down between the aero bards. There's two pockets, a tall skinny one for my GPS, and a smaller boxy one for my camera/cellphone. Everything else went into my trunk bag, and I added two Bento Boxes for the snacks I wanted to have available.



This link : http://www.thirdwave-websites.com/bike/trek830.cfm
has a few more pictures of the bike with the aero bars on it.