If you want more counter and storage space, then adding a center island may be worth the cost. But an island can limit the number of people working in the kitchen, reduce traffic flow to one-way with no passing, and make for cramped quarters. Try out an island before committing to one. Slap together a full-scale model out of cardboard or plywood and live with it for a few days. Make sure you can open your stove and refrigerator doors. No space for an island? Consider a kitchen trolley instead.