Twinlakes, I have a Thermador downdraft dual slide in range. I love it. It is in the peninsula, or will be when my contractor gets it back in. We bought it in 2001. We have had two service calls, neither of which were serious. I love that I don't have a hood obstructing the view of the rest of the room. We like it so much we decided to keep it instead of replacing it during this remodel. When I need a new one, I will get a downdraft again.

This is a pop-up downdraft. I push a button and it comes up out of the counter. When I am finished with it, it goes back to countertop height. I think this type is more powerful than the downdrafts that are in the middle of the range top. I don't know what it would do to a window. I would check out Thermador. I know there have been lots of improvements since we bought ours.

I remodeled a kitchen in which I was forced (by cost constraints) to use existing downdraft venting on an island cooktop. We installed a Thermadoor downdraft and a Thermadoor cooktop and used a good in-line blower. On the back burners the downdraft is strong enough to pull down all of the steam/grease/etc. from all but our tallest stockpot (and even for that it does a pretty good job). On the front burners the downdraft is mostly useless. For that reason especially, I think it is best to use induction (or electric) rather than gas with the downdraft. And certainly it's best to avoid a powerful pro style range or range top with a downdraft as I cannot see how you would be able to get all of the front burner gas out of your kitchen. If you do get a downdraft be sure to get one that is as tall as possible and don't skimp on anything related to optimizing your ductwork and blowers - it's pretty complicated stuff and you have to find an appliance store and/or installer who knows what they are doing.

If you haven't already, I suggest you check local building code on placing a range directly beneath a window.

mine is a decor with a wolf cooktop in island. it's fine. don't do much serious cooking but also didn't want to block the view.

Had the Thermador pop up for 26 years, worked fine!
We had the grill/griddle and used it often, never had a smokey kitchen...

Anyone who knows kitchen design knows that only 10% of your time spent in a kitchen is actual cooking and would never design a whole room around a 10% usage. There is always a better spot for a cooktop than in the middle of your view when you are planning new construction. You just need an actual KD who cooks to show it to you. And be open to listening.