Summary: Mio C520 has lots of breathtaking properties that makes it one of the best navigation devices in the market: 1- The GPS receiver is very powerful. 2- The maps are understandable and well designed. 3- 4.3 inches is the optimal screen size for a GPS device, and Mio C520 has it. 4- Text-to-speech works great on this device. 5- Fast and accurate re-routing, when you miss an exit or a turn. 6- There is that "jailbreaking" method available for Mio devices.