I love my griddle and the versatility of the cooker. It is my newest cooking tool so it is all a big adventure or trying different cooks that simply make a huge mess in multiple skillets in the house. Less oil is used and the odors and airborne grease from frying is all outside and not on my cabinets.
I love my grill and the flavor of the fats smoking off the flavor bars smoking up through the meats. It is the highest temp cooker I have so it is cooker of choice for super hot cooks and sears.
I love my smoker and the tenderness and juicy meats it produces. There is something special about the wood smoke collecting on the meats. And smelling that smoke for hours as your special treat is cooking will drive a person insane. It's more powerful that smelling bacon frying.
All cookers have their merits. All cookers take some amount of attention and cleanup. If I were forced to choose just one outdoor cooker I would be hard pressed to make a decision. I would consider what we like to eat and what cooker does the best job cooking it. Which cooker is the most versatile and might last me the longest for my investment would definitely weigh into my decision.
I sat here staring at my cursor blinking at the end of the previous paragraph where I was going to type just what cooker I would have if only one was my option. I could not choose. I love all three cookers, and if need be, I would quickly replace a failed unit.
I no longer cook in the house. I cook something outside daily. It's a cheap hobby when you consider you have to eat something anyway. The odor and the mess is all outside and the food produced is superior to what I can prepare inside. And, I just get off on griddling, grilling, and smoking.