I use one and have done for 5 years. Made a world of difference in my work life. Used to feel tire and nodding off. With CPAP I get quality sleep and do better work.
I don’t wear mine at work. People would stare.
My first rig was just a glorified aquarium pump 10 years ago and I made a doorstop out of it. Noisy as hell. My wife ended up making more noise that any machine could and I tried again last year. These new gizmo’s are really nice / quiet and relatively unobtrusive all considered.