I can’t speak as to why others use Visonic sensors but in my experience they just work, they don’t drop off and I’ve had zero issues with them. I was just happy to find that they have a version now that has a 5 year battery life! Once a year doesn’t seem like much until you have to go around and change 32 contact sensors. In comparison to other sensors I’ve purchased the Visonic has worked flawlessly and Comcast charges $50 per sensor for the same ones so I thought it was a great deal. I’d speak to some of the more experienced users on here for a more technical answer.