I must still say, though, that NR's and their cousins provide the most natural hand position available on any type of handlebars. One can choose other types, but soon discover that you are squirming about all over the place trying to find that sweet spot.
I have to agree, especially about the natural hand position. Just sit there and let your ams dangle; rotate your forearms out and you feel pressure, rotate them inwards and you feel a different pressure -- but right in between is that sweet spot. Now, swing your arms forward, and your hands would land perfectly on the grips of NR-type bars.
Now, they make it more difficult to tuck out of the wind, and they feel weird when pulling the front wheel over a curb. But, I think they're one of only a couple really good options for riding in an upright position.
+1 on the Ergon grips, too. Even if you have some other kind of "ergonomic" grip, you can maximize its potential by orienting it the same way as Ergon recommends for theirs. It took me a while to really be sure about the angle on my pair of Ergons, but after a couple months of setting them not-quite-sung-enough, which allowed me to tweak them without tools, I got them at an angle where they feel really good.