Handlebars - Narrow or Aero?

I am enjoying this thread, I think I might bite on some narrow bars soon (currently on 40 C-C width, 71R, 118D). I love the bars im on and just wonder what doing more narrow would be like.

While reading this thread I remembered that Nextie has a source on bars similar or knocked off of the Speeco. I have tons of Nextie products, they are pretty good but anyway they are significantly cheaper for anyone wanting to try a bar like that out.