I've never had geoduck in a raw or stir fry presentation, but have had them numerous times as pan fried cutlets or pan fried geoduck strips, so to speak. This is a true delicacy! They are pounded, cut, breaded and then pan fried in oil/butter. (somewhat similar to pan fried razor clams only sweeter, I think, more like how I used to remember abalone tasted, although it's been years since I had abalone). Our family is fortunate to share a beach with Taylor Shellfish Farms (they are the largest producer of clams on the west coast) See article: Farming the Tidelands
near Shelton, WA, and we have sometimes been the recipient of the generosity of the shellfish growers when they are harvesting. They are growing geoducks by the thousands in several little inlets in Puget Sound, including the one where our beach house is located. Up until about 4-5 years ago they grew oysters on our beach, but have switched to a more profitable business of Geoduck's. (note: they still grow oysters on the other beaches, as well as mussels, manila clams, scallops & crabs, but our particular beach just has the geoducks, and a few wayward oysters also remain).
We have also had the experience of digging a natural growing geoduck one time. It was buried in a mix of sand/clay. It was really hard work digging that one up, and then when we fried him up, he tasted of the clay he had been buried in all those years. That's not an experience we will repeat! The farmed ones taste MUCH better!