Product review (2 stars): Has good and bad features but a significant safety issue.
I bought this unit less than a year ago and it works well. But there are some problems.

Here are several tips for getting the best performance from it:

1. Turn the unit on five or 10 minutes before you start cooking, to get the airflow started.

2. install a "make up air system". This adds significantly to the cost of the downdraft installation, but is required where we live. The system serves to provide additional airflow into the downdraft  so that you have a good complete circuit of air into and  out of the house.

There also are a few negatives about the system:

1. Having the remote blower in the basement does not reduce the noise at all. It is just as noisy as a system with the blower unit directly underneath the cooktop.

However, one big advantage of having the blower in the basement is that you have all the space under the cooktop for storing pots and pants.

2. There is a large overhang on each end of the top of the vent intake (the piece that goes up and down) which makes it easy for objects to be pushed under it unintentionally. Then when you push the button to lower the unit, the overhang pushes down on the object and continues to close. Pressing the up/down button has no effect, as the unit is designed to open completely and close completely before changing direction. If you are lucky, you can pull really hard to get the object out from the closed vent intake. But I would hate to see what would happen if it were somebody's finger.

The owners manual says that if an obstruction is interfering with the vent intake movement, you should "immediately press the up/down switch, then disconnect the power plug. Remove the obstruction. Reconnect the vent power plug and press up/down switch to raise or lower intake." When I got an object stuck under the unit's overhang, it took me a while to find the owners manual and follow the instructions. However, the unit no longer moves up or down. A repair technician said that he probably needs to replace the motor  and the lifting arm.

I wonder whether, if I had immediately pressed the up/down button and unplugged the power (which is in the basement and needs a ladder to reach), the unit would still be functioning. I guess I'll never know. It seems to me that this is a significant safety hazard and a design flaw that Dacor should fix immediately. If they modified the system so that the vent intake stops moving when you hit the up/down button, that would make it much safer to use.