Over the years I've used a number of similar insect killers, and I find that they work well.  They don't control everything, but they definitely have had an impact on the flying insect population.  We have a large second-story deck (16' x 40') on the back of our condo and I wanted a solution that would help draw insects away from us.  We don't have a great deal of grounds around us, so I mounted this at one corner under the deck, and it works great.  I'm continually amazed at the quantity of insects it eliminates.