It goes without saying that higher battery life is always better. However, in most instances, one day battery life is all you need. Use through the day … charge at night. Apple clearly scrapped its sleep tracking features for this version because otherwise there would be no good time to charge it. You don’t want to unstrap something at midday just to ensure it can track your sleep patterns in the evening. There’s a natural cycle of how human beings live and the Watch mirrors that. I think 24 hours of longevity is perfectly acceptable.