I have the GLM42. I use it weekly measuring office walls for interior remodeling. They are a great asset,accurate and much easier than stretching out a tape measure. The GLM50 has bluetooth capability ,that I believe with a Bosch app and a smartphone/tablet allows you to layout a room and the dimensioning transfers to the app and "draws" the rooms/walls. I have not had a big reason to switch/learn the GLM50 and app but a few more complicated jobs and I just might.