... or not.

2 years ago I built a wheel with the Sram Automatix. Rode my SS bike with it for about 400 miles, it tested my patience to the point that I gave up and retired the wheel.
Here is why:
The hub upshifts very reliably, but the downshifting is inconsistent. Sometimes it would downshift right away, and sometimes it won't - until I did more than one "kickbacks" well after my speed had dropped under the speed at which the clutch pawls get disengaged (about 12 mph in my case). This meant that preservation of momentum was completely lost.
I can not attribute this deficiency to poor build of the hub or lack of maintenance, since I had it opened up and cleaned several times. I have seen accounts on other forums sharing similar experiences, but I had to try for myself since I am a stubborn skeptic.

This hub is not made for rolling terrain where downs are followed by ups, and a rider would be wise to take full advantage of his momentum during a undulating climb. It is made for urban type of riding, where the rider does not need the downshift to take place right away, but instead is tolerant to a prolonged coasting (several seconds) at a lower speed before the need to be in gear is felt. Good for the city, awful for performance riders who want to maintain momentum in steep terrain.