https://www.cnet.com/news/apple-watch-fitness-claims-to-the-test/

After testing out the Apple Watch Series 4 alongside the Series 3 for about three weeks now, I've noticed two major advantages over its predecessors when it comes to working out: screen size and battery life.

The first thing I noticed when I took the Apple Watch Series 4 for a run was how much easier it was to read the numbers. It's one of those things you never notice until it's improved upon, and all of a sudden I found it easier to track my heart rate and check my pace and distance, without having to squint at the screen and risk a stumble.