Choosing a Viking cooktop with downdraft ventilation can be beneficial if you desire a sleek and unobtrusive kitchen design. Downdraft ventilation systems are integrated into the cooktop, drawing cooking fumes and odors downwards rather than requiring a separate overhead hood. This can save space and allow for more flexible kitchen layouts. However, downdraft ventilation might not be as effective as overhead hoods in capturing all cooking byproducts, especially for high-heat or heavy-duty cooking. Consider your cooking habits, kitchen layout, and ventilation needs when deciding. If efficient odor and smoke removal are essential, an overhead hood might be a more reliable option.