I had a kitchen about 15 years ago that had one of these in the island. I really didn't care for it, though. It was very noisy, and I also think it didn't do it's job properly. Not much was sucked out, either grease or smoke or odors. It had to suck out the back of the cook top, and I believe it's much better to have the vent over the cook top to be effective. But, like I said, it was about 15 years ago, so technology may be a lot better now. HTH, Val

Smoke and steam rise. You're attempting to contravene the laws of physics by trying to suck it back down rather than just trying to capture it and duct it to the exterior. That comes at a price of a louder fan and less effective ventilation. It's worth it for some to maintain an open view, but for most people the 10% of the time that they actually are standing at a stove it works out to be a more functional and less expensive layout to get the cooktop off the island and onto a back wall. Then put your prep area on the island where you'll spend 70% of your time in the kitchen.

For those of you following my comments - if you go over 300-400 cubic feet per minute, many states require make up air handling systems at $5000+
I really wanted one of these (despite the laws of physic) and discovered that they were all large air handling monsters that would have cost a fortune to put in the MUA system.
I was bummed but in the end, it forced me back to a more traditional system which is better anyway. As I have learned with sports clothing - sometimes function is better than fashion!

Emily, if you do a search for "downdraft vent" on this forum, you'll find a number of threads discussing the pros and cons of this style:

Here is a link that might be useful: Downdraft vent threads here at the Kitchen Forum