The device was very easy to set up, and I've used the Alcosense Excel a few times now; it's very easy to use. I've used it just for interest within an hour or two of drinking, and again the morning after before driving. The readings seem accurate, and so it gives me additional confidence that I am OK to drive, and don't have to worry about being breathalysed by police if I'm involved in an accident (my fault or someone else's).