Here is a quote from Michael that seals the deal on buying one myself. Note near the end he said it will excell at both SD and utility use. And from what I an gather was designed to do both well.
The original custom Mike Snody versions of each were chisel ground. The Spyderco versions of both the Ronin and Yojimbo are full double flat grinds.
To provide the definitive answer to the utility question: Much of my research on blade shapes for short knives was based on cutting tests, primarily on meat and foam targets covered with clothing. I tried many different blade styles and used everything from high-end custom tactical knives to -- quite literally -- box cutters. The performance of a Stanley utility knife in cutting tests is amazing. When I learned more about why this is often a weapon of choice on the street, I came to consider the wharncliffe to be an ideal all-around blade shape.
The Ronin and Yojimbo designs both pre-dated 9/11, but were not comercially released until well after it. Out of respect for the victims of that tragic date and their families, I did not want any reference to box cutters in the early product descriptions. Now that some time has passed and it's easier to consider the blade function more objectively, I'll admit that the wharncliffe design of the Ronin and Yojimbo was very much inspired by utility knives and box cutters.
The other aspect of the wharncliffe design that many people fail to appreciate is its function as a thrusting weapon. The physics of the design allow it to puncture as well as any dagger, but typically prevent it from binding.
Adding these aspects of cutting and thrusting performance to the handle of the Yojimbo, you have even more advantages. The handle is designed to fit the anatomical structure of the hand and provide an ideal compromise for fans of hammer, saber, and Filipino grips. The deep finger choil is also as effective a guard as one could possibly want. The closed knife is designed to provide both focused and blunt impact surfaces and pressure-point and point-compression capabilities. The tapered design also guarantees a snag-free draw, and the radius and leverage points of the Spyderco hole support exceptionally quick openings.
If you consider a Stanley utility knife a good EDC tool, the Yojimbo is even better. And all the features that make it a good MBC tool also enhance and support its utility use. After all, cutting is cutting.
Stay safe,