That is the question du jour. It may have been easy to dismiss the santoku as just a bit of trendy fluff initially but I find it extremely useful. I will never give up my good French chef's knife however. The big difference is in size, both length and handle. I have small hands so the santoku fits me so well that it easily becomes an extension of my arm and in an Eastern sense of my mind. There are still jobs that I use the big knife for however. They are much sturdier. I found that the santoku took some jobs from the big knife but took many from my small knives as well. In the end this will come down to individual preference. Do you find small knives comfortable or not? The answer may be telling. Whatever choice you make pay more than you think it should cost. There is no substitute for quality in your cutlery. Wusthof and Henkels are my prefered brands. Whatever style blade you choose plan to spend $100-$400 per knife. It goes without saying to always hand wash and never to store in a drawer. Here are some discussions of the two knife styles.