Functionally, nothing beats the center box pleat. It adds a lot more fullness to the back. The downside is that it also adds fullness to the waist in the back. 'Course more fullness there will help with movement as well. In my experience at least, shoulder pleats are next to useless--the extra fabric you'd need for movement needs to come from lower down the back where they don't give you much extra. But if the shirt is cut right, they can look a lot cleaner. It also might depend on how your back is shaped. For me at least, a center pleat falls between the blades naturally, but side pleats sit on my shoulder blades and kind of stick out oddly. Centre box pleats don't really do anything other than balloon out at the middle of the back. They add fullness is the wrong place. They just look messy. And they're even worse if you're wearing braces. Side pleats look cleaner, and I find them more effective because they are over the shoulder. Your shoulders move more than the middle of your back, which is why it's more effective to have the pleats there. They way your body is shaped makes more sense to put the pleats at the side.