The basic setup is the GPS highlighting the path you're supposed to follow. You don't have to keep looking at it: a quick glance when you're coming to an inter

The basic setup is the GPS highlighting the path you're supposed to follow. You don't have to keep looking at it: a quick glance when you're coming to an intersection, to know if you have to slow down and get ready to turn or just keep going. As other said, it can also provide additional features like warning you about cars coming from behind or reminders to eat/drink. And contrary to some other comments, it's not another screen asking for your attention. Setup correctly, it's just a map that refresh itself and follows you. Allowing you to focus only on your sensations, instead of having to think about where you are, where you're going... Finally, cue sheets are nice, but even if you don't care about being "lost" or having to find your way by yourself, you'll probably end up on bad roads with lots of traffic. Meanwhile, if you're just following precisely a nice route going only on quiet roads/paths, you won't end up in bad situations and you'll find your ride more enjoyable.