Fun stats, to be sure! Interesting though as there is no comparison as to the phone itself. Ease and speed of placing and receiving phone calls plus the speaker quality of calls- outgoing and incoming. No comparisons there. Same for text messaging.
Would also love to see a testing with each iPhone on its original iOS. For example, an iPhone 4S runs smoother and faster on its original iOS vs iOS9.3.5
The iPhone 8 is tested on its original, in-the-box firmware yet the other iPhones are not.