The iPhone 6s Plus iOS 9.2.1 update offers a solid experience to users who want fixes for some iOS 9.2 problems and to jump to the latest software. While Appel does not pack the iOS 9.2.1 update with a plethora of features, it does address security issues and problems that plagued corporate users so there is an incentive to install it.
After using the iPhone 6s Plus iOS 9.2.1 update for a short period, and then trying the iOS 9.3 beta, the overall performance of the 5.5-inch iPhone 6s Plus on iOS 9.2.1 is good.
We no longer see the issue from iOS 9.2 that made the touch screen go unresponsive for a minute at a time. We've run into an occasional stutter where the screen stays black for a short period on other devices, but it is not happening on the iPhone 6s Plus with iOS 9.2.1.
Overall the iPhone 6s Plus delivers good connectivity on AT&T LTE with solid personal hotspot performance and good Bluetooth connectivity.
This is an upgrade that iPhone 6s Plus users can install without worrying about slow downs or hidden problems.