Apart from the double speed, Bluetooth 5 also promises to quadruple the range of broadcast. It promises a maximum speed of 48 Mbps for distances up to 300 meters. See a detailed speed distance comparison table between Bluetooth Version 4.1, Version 4.2 and Version 5:

Bluetooth 5 also introduces a new mode of operation known as long range mode. Devices operating in long range mode can sacrifice data rate to achieve longer range/distance of operation. Engineers at Texas Instruments have successfully tested the long range mode by connecting to a Bluetooth device 1.6 km away (yes, you read that right) with data throughput of 125 kbps. See the details of their exciting experiment at the link mentioned next.

This means, with the new wave of Bluetooth 5 fitness trackers hitting the market, you could now leave your phone in the car for your future runs at the park rather than having it strapped to your arm. 

The quadrupled range makes BLE 5 an interesting choice for the Internet of Things since devices can be connected over greater distances and cover larger surface areas (warehouses, malls, and so on).