I had this door installed after careful research. There are doors that are cheaper and quieter, but my need was for a door that could operate faithfully and securely. I live in the country and varmits of all types (skunks, raccoons, possums, and even neighboring dogs) surround me. This door handled the security issue perfectly.
I agree that it is slightly on the noisier side but I'm not complaining if the motor and moving parts make it worth the money and it has. Very solid. It has a metal belt instead of a thin cable and three years of constant operation attests to good engineering and construction.
I had a professional carpenter install my door because I needed it between a large double window door and a picture window. I had no room for error. His first pet door of this kind and he had no problem with the directions that came with it.
The entry key was another crucial component because my dogs love to jump into lakes, creeks, and their kiddie pool. I've yet to have a problem. A life change that included a girlfriend with her own pup increased the utilization and I'm still impressed with its durability. Yes, the two taller dogs stand close to the door but they mastered that in just a couple hours. My shorter pup simply raises his head a little taller and has no problem... he even opens the door occasionally just to peek outside. I love the fact that my boys have the freedom to escape the weather and yet take care of business without waiting for me to be around.
I had forgotten that the original color of the sliding door was black because I immediately painted it to match the interior room color. That makes it blend in with the window and door trim and it catches guests by surprise when it operates. Think "Star Trek" elevator door!
Overall, I'm very pleased with my 3-year old investment.