The most noticeable change is that the OLED display is bigger. The standard model is now 40mm high by 34mm wide (up from 38.6mm by 33.3mm), while the larger model is now 44mm high by 38mm wide (up from 42.5mm by 36.4mm). However, as the bezels around the display have been slimmed down, the Series 4 has not gained any significant overall size.

In fact, the Series 4 is thinner than the previous version (10.7mm compared to 11.4mm), so it sits slightly flatter on your wrist. For me, that means it is not getting stuck on my sleeves so much while removing jackets.

The larger display allows for bigger text and more information. It can also now display up to eight complications (essentially small widgets that sit on the watch face), up from four. Viewing photos, navigating with Apple Maps and playing games – yes, there are games for the watch – are easier on the eyes and feel less silly than before.

Apple has continued its focus on pushing the watch as a health device, with the Series 4 adding a new electrical heart sensor and an 800Hz accelerometer and gyroscope. The sensor can perform an EKG (electrocardiogram) while the accelerometer and gyroscope can supposedly detect when someone falls over and alert emergency services automatically if the user remains unresponsive.

However, the EKG feature isn’t ready yet (it will come via a software update) and I was unable to trigger the fall-detection feature despite making over a dozen premeditated falls at the gym on a cushion. Either fall detection works so well that it could tell my falls were staged, or it doesn’t work much at all.

Software and features

While the watch’s hardware is excellent, it is the software that makes it the best smartwatch around – an opinion shared almost universally by reviewers.

Apple’s WatchOS (now in version five) completely outclasses Google’s Android Wear, Samsung’s Tizen and Fitbit OS, whether it is in navigation fluidity, third-party app selection or a number of other areas.

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The raise-wrist-to-wake-screen gesture, for example, is hit and miss on Fitbit and Samsung’s watches, leaving me never sure whether the screen will turn on if I don’t have a free hand. On the Apple Watch, it is on point every time.

Taking phone calls or responding to notifications is also much smoother on Apple’s device than other smartwatches, as WatchOS transcribes what I say with accuracy and speed. Scribbling individual letters on the watch face also works like a charm.

One nitpick, though, is the watch’s inability to track sleep out of the box – it requires a third party app that costs money.

Performance and battery life

A new S4 chip set powers the Series 4, and Apple says it is twice as fast and efficient as last year’s set.

It is hard to tell any speed improvements considering the Series 3 was already an excellent performer. I experienced no stutters or lags during my week with the watch.

The improved efficiency, however, is noticeable: battery life on the Series 4 is slightly improved, lasting a bit more than two full days on a single charge. Other smartwatches though, such as Fitbit’s Versa, offer an extra day or two of battery life.

Conclusion

The Apple Watch has been a smashing success for a couple of years now – in the last quarter of 2017 it outsold the entire Swiss watch industry – and the larger screen and thinner form factor of the Series 4 make the best even better.

It is quite expensive – prices start at HK$3,199 in Hong Kong or US$399 in the US – but have high prices ever stopped Apple fans? For loyal iPhone users, this purchase decision is likely a no-brainer.

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Android users, however, are out of luck, as the Apple Watch can only work with iPhones.

Price: HK$3,199 (40mm, base GPS version); HK$3,399 (44mm, base GPS version); HK$3,999 (40mm, GPS + LTE version); HK$4,199 (44mm, GPS + LTE version)