Data from analytics company Chitika suggests that 61% of compatible Apple devices are running the software, which was released in mid-September.
iOS 6 introduced a range of new features unavailable to iOS 5 users, but was heavily criticised over its Maps application, which was plagued by inaccuracies.
The service, developed in conjunction with TomTom, served as a replacement for Google Maps following Apple's decision to terminate its contract with the search engine giant.
Despite the disastrous Maps launch, more than 15% of iOS users downloaded the OS within 24 hours, a figure which took just two weeks to reach 50%.
Chitika speculates that iOS 6 adoption will surge after Apple's product unveiling this evening (October 23), which is expected to see the unwrapping of the so-called iPad Mini.
Watch Digital Spy's video review for iOS 6 below: