Generational iPhone tests are always so much fun. In one test, released by the YouTube channel EverythingApplePro, the narrator lines up all 15 iPhones from the 2G through the 7+. He compares speed, as well as the volume decibels, camera, touch identification, and heat.The iPhone 7 is said to be 120 times faster than the original 2G, which came out a whopping nine years ago—that's a lot of progress in less than a decade. Now, according to the video's narrator, "we're at a point where we're seeing diminished return on speed with new phones," which is why he filmed the speed test comparison.He plugged all the iPhones into the same port hub so that he could turn them all on simultaneously and watch which ones loaded first. The first to turn on was the iPhone 7, but the 7+ came in eighth place (out of 15), right after the 5s. The 4 came in last place.The narrator also tested the speed with which the camera application would launch, finding that the 7 and 7+ were not the fastest. The cameras themselves, however, on the latest two iPhones are worlds better than those on earlier versions. A side by side comparison of night shots, closeups, and color shows how much more clear, bright, and reliable they were in different settings.The narrator also compares the decibels on all the different iPhone iterations. Without a headphone jack, the iPhone 7 and 7+ were found to have much greater volume capacity than their predecessors. He also compared the heat emitted by the different phones, finding that the newer ones were overall cooler, but that the larger plus models, in general, emitted more heat.So while the iPhone 7 and 7+ may not be groundbreaking, when all the incremental change among iPhones is compared cumulatively, it's fun to see how much progress has been made. Even if it's not perfect.