Navi with weaknesses

The Navi is only conditionally recommended. I use it every day in the field and the performance of the cards and the presentation or announcement is mixed. The announcements are partly incomprehensible, especially under time pressure at "confusing" education and driveways not always easy to understand. The biggest problem, however, the satellite acquisition. It's very annoying to have to wait after the exit from the underground up to 3 minutes until the Navi decide in which direction we need.
For private use in order but every day with many changing goals rather poor.