I comute on a flat bar road bike. I put the aero bars on for additional hand positions and to defeat a windy day. I now spend 80% of my time in the aero bars because it is more comfortable and it typically lets me upshift 2 gears. I don't have traffic to deal with on my commute so that isn't an issue. I'm getting more comfortable going into corners in the aero position too.

I think they look dorky... but I wouldn't readily give them up!