iOS adoption over the years has slowed down somewhat. This is because in previous updates, Apple’s QC has been slightly questionable which resulted in phones performing worse after updates, or being hit with a ton of annoying bugs. If those are some of the reasons that makes you hold back from adopting the recently released iOS 12, perhaps this might change your mind.
In a series of tests conducted by ArsTechnica, they have found that iOS 12 actually improves the performance/speed of older iPhones. They tested this out on the iPhone 5S, iPhone 6 Plus, and the iPad Mini 2, and found that compared to previous versions of iOS, iOS 12 actually does deliver what it promises, which is improved performance on older devices.
They compared the speed of iOS 12 amongst a variety of older iOS builds, dating back to iOS 10.3.3. They then tested it by launching a bunch of apps. Take for example Safari which in iOS 10.3.3 took about 1.2 seconds to launch. This worsened with iOS 11 where it took 1.5 seconds, but come iOS 12, it actually went down to 1.15 seconds.
The camera app also saw similar improvements where it took 0.9 seconds to open in iOS 10.3.3, to 0.81 seconds in iOS 12. That being said as Ars notes, how long an app takes to open isn’t necessarily an indicator of how the apps will perform when they are open, but overall it does show that improvements have been made. So far there haven’t really been any major bugs that have been reported yet, so maybe updating to iOS 12 could be worth taking a look at.