Excellent pedals--they rotate easily and are easily adjusted for ease in clipping in or out. I chose the long spindle model as I tend to hit my right heel on the chain stay on some of my bikes. I prefer the cleats with +6/-6 float and the extra length of the spindle allows for easy chain stay clearance.
I was looking for a pedal with a wider center point and didnt want to use any extenders. These pedals have just what I needed. Just a few mm made the difference. Nice and lite being carbon.
The wide chain stay spacing and shorter stays on latest generation road bikes (i.e. Cervelo and BMC) seem to require a wide-Q pedal spacing. This pedal really solved the problem of my heels hitting chain stays, by moving the spacing out just enough. Great pedal and perfect solution to short/wide rear end dimensions on newer bikes.
the dura ace 4 pedals are lighter and smoother than my ultegra, which had 6000 miles on them. I got them on sale and was a great investment. If you ride with your knees out like cowboy style the 4 spindle is for you. I wish I would have had these long ago.
Dura-Ace pedals are lightweight, offer adjustable release tension, are easy to get into and out of and offer a range of float (depending on the chosen cleats).
There are other pedals lighter in weight, there are other pedals with different entry and release systems, there are other pedals with more float. None that I've tired so far, though, whether for road or mountain, put it all together as well as Shimano does. For me, an extra benefit I appreciated was being able to buy these pedals with the longer spindle, which better suits my relatively wide feet.
Dura-Ace pedals are top of the line and so are justifiably expensive. They are occasionally on sale, though, and prior years' versions can of course be had at a steep discount.