Apple's iOS 12 has been available for less than two weeks, but that's enough time to tell that iPhone owners are far less eager than they have been in the past to update their devices, according to a Mixpanel study.

Over the first 10 days that iOS 12 has been available to the general public, only 20.7 percent of those with iPhones downloaded it. That's considerably lower than the download rate for iOS 7, which saw a 63.4-percent adoption in its first days.

The iterations of iOS have gotten less spectacular since Version 7, which Apple CEO Tim Cook had said was "the biggest change to iOS since the introduction of the iPhone." It marked the end of the skeumorphic era and the embrace of digital-first design that focused on animations and multitasking.

Those who have updated to iOS 12 have been able to play with Memoji, can see how much time they're spending looking at their screens, and are using Siri Shortcuts. But they can't make as-promised 32-person FaceTime chats.

The lackluster adoption could be due to a lack of interest in the features. But users might also be waiting to see what issues arise with the OS. Though every version of iOS goes through testing before its release, we've experienced some less-than-welcome surprises, such as the battery-life debacle of iOS 11. There are reports right now about iMessages going to the wrong recipients, which is a nightmare scenario for pretty much anybody.

Apple is still proud of its iOS's adoption rate, however, particularly compared with that of Android. Vice President of iOS, iPad, and iPhone Product Marketing Greg Joswiak said in an interview that the upgrade rate for iOS is far higher than for Android, and he expects 80 percent of users to be on iOS 12 within a few months.