As expected, Apple has begun rolling iOS 11 out to iPhones and iPads today in most regions. You can probably download it right now, and, if not, you’ll be able to fetch it very shortly.

Devices as far back as the iPhone 5S, the iPad Air, and the iPad mini 2 can update to iOS 11. But the iPhone 5 and 5C, as well as the fourth generation iPad and the very first iPad mini, are not supported by iOS 11.

Ars tested iOS 11 on an iPhone 5S and found that the device predictably ran a bit slower than it did on iOS 10, but it’s not necessarily deal-breaking. For example, launching, force-quitting, and re-launching Apple’s Mail app took 0.4 seconds longer in iOS 11.

More than your hardware, though, you should consider app support before updating. iOS 11 terminates support for 32-bit apps. Assuming your phone has the most recent updates before iOS 11, you can check which of your currently installed apps are not supported. Just open the Settings app, go to General, then About, and then Applications. You’ll be provided with a list of incompatible apps.

You get a lot in exchange for that tradeoff, though. New multitasking features abound, like a redesign of the App Switcher and dragging and dropping information between two apps in Split View. The app store has seen its biggest overhaul in some time—something that will have untested implications for app developers. Spotify-like social features have been added to Apple Music, HomeKit can now control smart speakers via AirPlay 2, machine learning enables new features in Siri and smart curation of “Memories” in Photos, and the Control Center has been redesigned for efficiency.

Some expected features, like Apple Pay in iMessages, didn’t make it for the launch but are still coming later.

The dark horse of this update could arguably be ARKit, which will have some at-launch app support. But we expect it to open a floodgate of new AR applications and features across the iOS app ecosystem.

In any case, check out Ars’ detailed review of iOS 11 to dive into the details of what you’re getting with this update.

Apple also rolled out watchOS 4 to supported Apple Watches. WatchOS 4 brings a number of aesthetic changes to the watchOS interface, plus a Siri watch face, a new HIIT workout, and improved swim tracking. It also adds GymKit, which allows interfacing with exercise equipment, but that won’t be fully supported until later this fall. Expect our in-depth review of watchOS 4 in the coming days.

The new Apple TV software, tvOS 11, also landed today. The software adds live news and sports, AirPlay 2 support, and a handful of other minor tweaks. It’s available for fourth-generation Apple TVs.