About 7 years ago I bought a nice Shun 8-inch Santoku (I have kind of large clumsy hands). At first, it sat in the drawer because I didn't care for the somewhat flat blade edge. I had been brought up using a rocking motion to cut vegetables, which seemed better suited to a standard European chef's knife, due to the rounded edge. The Santoku felt a little awkward by comparison.
Anyway, we had some kind of event at the house where I needed some kitchen help, and so I started handing out knives and cutting boards to people. All that was left for me was the Santoku (sorry, but I wasn't going to hand a $200 knife to people I didn't know real well). Again, it felt clumsy at first. But I found that by rocking it more on the tip, I could get the same sort of technique as with the chef's knife. And the more I used it, the better it felt. You definitely get a little better sense of control over the shorter, thicker blade. And speaking of the blade, the blade on this thing is wickedly sharp. Onions and carrots quiver at the sight of this knife.
Before long I was using for all my vegetable prep work. I still don't care for the shorter blade quite as much when cubing large cuts of meat for stews and what not, but for most everything else it rocks!
The only thing I will add is that you MUST have it sharpened by someone who understands the angle of Japanese knife blades. Or buy a sharpener with the correct angle. I didn't understand this at first, and almost ruined the knife when I sharpened it the first time. I ended up having to send it to a manufacturer-sanctioned sharpener to have the blade re-honed. Now that I know, I do it myself.