We have a Viking 36" rangetop with a matching Viking downdraft vent, installed in Feb 2003. No problems at all. BUt the vent does not work all that well, especially for heavy duty wok cooking. If you do a stir fry once a month, maybe burgers every few weeks, it'll be okay. But you won't be really stir-frying with 15K BTU burners. Wok burners are typically 30K. Just be prepared to repaint the kitchen more often. We have a high ceiling and an open floor plan and no issues whatsoever.

Just understand the limitations.

PS, the really belongs in the Appliances forum, where you'll get far more responses! Or maybe Kitchens.

Good luck!