In this video I review the Xiaomi Watch S4 41mm, which landed on 24th September, and I’ve been lucky enough to test it for over two weeks. The big question I wanted to answer was simple: is the 41mm actually worth it over the original Watch S4, especially when the standard one is currently around £20 cheaper? So I break down what’s the same (like the 60Hz display, 5ATM water resistance, 150+ sports modes, similar watch faces and controls, and the same easy-to-use companion app), and then I focus on what’s genuinely different. The 41mm is smaller and thinner, so it looks a bit more elegant in real-world lighting, and it’s got a higher pixel density screen because of that smaller size. It’s also stainless steel all-round, adds a thermal/skin temperature sensor, and uses Xiaomi’s newer T1 chip that’s claimed to be 35% more efficient. The trade-off is battery: the original can do up to 15 days, while the 41mm is rated up to 8 days. In my testing, tracking (steps, heart rate, sleep) didn’t throw up any red flags when compared against other watches I trust. My conclusion is a no-brainer: I’d pick the 41mm. The lighter, thinner feel is the dealbreaker for me—especially for sleep tracking—while the battery is still easily strong enough for day-to-day use, and it charges quickly anyway.