One of the differences between these two devices, the most basic one is that the first is a smartwatch and the second is a fitness and wellness tracker.
If you want a fitness tracker but are not really interested in smartwatch features such as making calls from your wrist, then the Fitbit Luxe will be better for you.
Both the Fitbit Sense and the Fitbit Luxe have remarkably good batteries that last days on end. However, the Sense is the clear winner here because you can get up to 6 days of battery life out of it. The Luxe comes in second with up to 5 days of battery life.
Which is better for battery life, Fitbit Sense or Fitbit Luxe?