Being one of life's skeptics, I was dubious about this product to say the least (especially at the price), but having researched and read lots of reviews, it seemed the best option for our downdraft issue (smoke filled room almost every time we lit the stove - my wife banned me from using it!).
Yes, there are much cheaper options on the market (which I must confess I have never tried) but none of them offered the full package of low maintenance (no moving parts), easy to install (although managed to get our builder to do it for free!), works in all conditions (windy and still), etc. I'm delighted to say I have tested the cowl in various weather conditions, and have yet to find any that cause the downdraft and resulting smoking. This appears to be science at it's best, so in my opinion merits the steep price tag - I would recommend this product to anyone having downdraft/draw issues with their wood burning stove. Now I'm allowed to light the stove whenever I want!