Apple released the first update to Apple Watch OS earlier on Monday—Apple Watch OS 1.0.1 (which is called simply Watch OS by Apple in some places)—and right off the bat we noticed that screen reaction times seem to be dramatically faster. Glances also appear to load more swiftly, and switching between notifications, the Watch face, Glances, and Apps appears smoother and faster.
Upon further testing, however, we found that some of those performance increases may be due more to our Apple Watches being restarted than the update itself. When objectively comparing Apple Watches upgraded to Watch OS 1.0.1 to movies of devices that hadn't been updated but had been restarted, we found no perceptible differences in initial screen reaction, swiping to pull down Notifications, and pressing the Digital Crown to switch between the Apps view and the Watch face.
With Glances, however, we did see smoother swipes and faster reaction times with some — but not all — Glances. In particular, in our limited testing, some third party Glances didn't perform as well as Apple's built-in Glances. Your mileage will almost certainly vary.
Below we have a screenshot of some of the emoji supported in the update, which is the emoji set included in iOS 8.3.
Apple Watch Emoji
We noted in our release coverage that the update requires your Apple Watch to be both connected to its charger and already charged by at least 50 percent before it will update. What we didn't note is that it takes roughly forever for the update process to complete.
Other improvements mentioned in the release notes include improvements to Siri, measuring calories burned, and measuring standing activity. Those features require more testing before we can comment on them.
[Update: This story was updated to include information from formal testing between freshly rebooted Apple Watches running Watch OS 1.0 and Watch OS 1.0.1. - Editor.]