Does it actually work or us it just over hyped feature?
Works well, in quality brands like DMT; Smith's is likely pretty good also. These hones do seem to be very easy to clean up as well, as much of the swarf will collect in the 'dots', and is easier to mop up as you go. DMT's 'Duo-Sharp' interrupted surface hones are also manufactured and guaranteed to be flat, within specific tolerances, whereas the continuous-surface hones (Dia-Sharp) aren't similarly guaranteed.
The biggest advantage of the continuous-surface hones (Dia-Sharp) is a more uniform scratch pattern, more easily seen in the finer grits. They also won't be a hazard to tips on blades, which can 'dig into' the recessed dots on the interrupted-surface hones, and will pose a risk of catching and damaging the tips.
With DMT, you really can't go wrong either way. They're both very good, and each have their own specific advantages. On bench-sized hones, either will be quite fast. I've tended to favor the continuous surface on smaller pocket-sized hones, because the total available abrasive surface area becomes more of a factor, in a smaller format. I also like the smoother feel of these smaller continuous hones, especially when holding the hone in one hand, while working the blade with the other. Smoothness translates into better control (therefore safer for my fingertips).
David