I had some Nitto ones and liked them OK on my Stumpjumper, but eventually switched to Midge drop bars. What I liked was pretty much covered by the previous poster. One negative is I like to use a bar mounted light and there was basically no straight part on the bar to mount one.
I have seen some people set them up with saddle-bar drop, but most say you want them level or higher. Also you will typically need a shorter than usual stem.