Apple Inc.’s Apple Watch Series 7 is the most refined version on the smartwatch yet, though not redefined by any means. On deck is a larger screen, stronger front crystal and faster charging that may warrant an upgrade from the Series 4 and below.

The standout feature from the Series 7 is its larger display. At 20 percent bigger than the Series 6, the display now hangs right over the rounded edges of the watch for a fuller image. It is most noticeable by full screen, color watch faces and much less by watch faces with a black background. The OLED display is bright and easy to read, even in direct sunlight.

The new green aluminum variant is a looker. It’s dark olive indoors to pair well with the new Clover Sport Band or a Golden Brown Leather Link. In addition, the chassis is more durable with a 50 percent thicker front crystal than the Series 6 and is now IP6X dust resistant.

Another great feature from the Series 7 is faster charging. Apple claims 33 percent faster charging than the Series 6 and zero to 80 percent charge in about 45 minutes with the included USB-C charger. In our test, the Series 7 charged from 30 percent to 100 percent in about 55 minutes.

In other metrics, the Apple Watch Series 7 remains largely the same as the Series 6. It yields the same 18-hour battery life, ECG and blood oxygen measurement functionality, and retains WR50 water resistance certification.

Also, don’t expect faster performance from the Series 7. The S7 processor utilized in the latest Apple Watch is said to be up to 20 percent faster than the Apple Watch SE, the exact same performance metric the company used when comparing the Series 6 S6 CPU to the SE one year prior.

Those with a Series 4 and below will see the most value from an upgrade to the Apple Watch Series 7, particularly with the bigger screen, more durable chassis, faster charging, and health measurements. Owners of the Series 6 or 5 should wait until more substantial changes are made.