This upgrade DT1775 model is superior to the DT1770, which I was already impressed with and had running for several years, non-stop. The fan finally quit. I live in buggy Florida and there are few solutions to the pests if you don't have a screened patio. A couple weeks after installing this, the patio has no pesky bugs! I still have to cancel our mosquito spray service to see if this device can do it all, but we've had mosquitos and other biting insects for years even with the service. The 1770 visually collected tons of insects so you knew it was working. This one, however, results in no flying insects being a bother. Over the years we've developed the habit of avoiding the patio. We are trying to break that habit. Look closely at my photos and you will see it captured a mosquito on the first day. The unit is far brighter than the old one, which might be a nuisance. For us, not so much as it is placed on the other side of a low outdoor wall from the patio. I don't like replacing the bulbs but I think that is the best option considering power, life, and other tradeoffs. I bought several bulbs and the upgrade allowed me to keep what I had purchased in advance. The diffuser in the DT1770 had to be replaced once somewhat early in it's life, but I think since then they improved the material. A major advantage (even at that time). This unit seems to be extremely effective, but as I mentioned, I have to dare to terminate the monthly service, which I'm not really up to doing, yet. Also, except for the four and a half foot wall, our unit is only 10 to 30 feet from the patio living space, not as far as the instructions say. I'd say that if space allows, even a skeptic should try it if they can return it in 30 days if not satisfied. Mostly preassembled, just add the bulb, I think. Should be easy to return.