Not sure if these apply to Band 1 as well, but for the Band 2, there are more choices to configure as to what it can show on the main and secondary screen during running and biking. You get three choices for the main screen and four for the swipable second screen. They are : Distance, Average pace, Duration, Elevation gain, Heart rate, Time, Instantaneous pace and Calories.
There may/probably are other changes but I haven't investigated them all yet.