We have grown accustom to the ergonomic handle bars that have come out in the last two years.  We like the Zipp contour bars the most due to the position of the flat surface on the tops of the bars.  A lot of the manufacture's have yet to get the position of the shifters to align with the tops of the bars, creating a large bend in the wrist. This wears on you over time.  We also like the vibration damping qualities of the Zipp bars; we find this particular bar to be more comfortable and can tell the difference within the first couple miles. If you're not riding carbon bars you should think about it.