One of the headline features of iOS 12 is that it should make every iPhone back to the iPhone 5s noticeably faster.
Apple's focus on performance in older iPhones running iOS 12 could help counter the negative publicity around its battery-throttling fiasco and the sneaking suspicious some people have that every new version of iOS makes their iPhone slower.
To keep iPhone owners happy, Craig Federighi, Apple's senior vice president of Software Engineering, said at WWDC that with iOS 12 Apple is "doubling down on performance".
iOS 12 promises to make everything smoother and faster, from app launching to keyboard display and swipe to camera.
At WWDC Apple said apps will launch up to 40 percent faster, while the keyboard comes up 50 percent faster. However, that was based on tests comparing iOS 12 with iOS 11.4 running on an iPhone 6 Plus.
SEE: iOS 11 tips and tricks for business professionals (free PDF)
With the first public iOS 12 beta out this week, ZDNet sister site CNET has now tested how much better things will be on the iPhone 5s, the oldest iPhone that iOS 12 supports.
CNET compared iOS 12 against iOS 11.4 on two iPhone 5s 16GB models to get a rough idea how iOS 12 performed under common tasks, like launching Mail, Safari and Maps, as well as the tasks Apple touted.
The good news is that even on this entry-level iPhone there were noticeable speed improvements, according to CNET. Launching Safari was 3.5 seconds faster on iOS 12, while launching Mail was a quarter of second faster.
Sliding to open Camera was also half a second faster, while the keyboard in Messages and Share sheet both came up one second faster. Lastly, Siri was half a second faster on iOS 12.
Hopefully, if results like this carry through to the finished release this fall, iPhone owners won't be feeling remorseful about upgrading to the newest version of iOS.
While performance improvements is the main focus of iOS 12, Apple also updates core apps like FaceTime, which now supports video calls with up to 32 people at once.
And for those with an iPhone X, there's Apple's new Memoji, a different take on its Animoji feature, as well as additional Animoji characters to pick from.
Previous and related coverage
All of which are currently only available to developers.
Apple iOS 12: Cheat sheet (CNET)
With iOS 12, Apple adds security features, performance enhancements, Group FaceTime, ARKit 2, and more. Here's what you need to know about Apple's latest mobile OS, which powers iPhones and iPads.
Calling 911 from an iPhone will soon automatically share the device's location with 911 centers.
Apple made a big deal of how iOS 12 would be faster than iOS 11, especially on older devices. But does the beta show signs of delivering this much-needed performance boost?
We put the iOS 12 beta on an iPhone 5S: Here's what happened (TechRepublic)
It's speed test time. This is what it's like to run iOS 12 on the iPhone 5S.
I took the iOS 12 beta for a test drive so you don't have to do it.