I have a Verizon iPhone 7 (bought from Apple for full price), which I am using on AT&T. The cell tower is about 100 yards from my house. I upgraded to iOS 10.0.3 two days ago, and I ran a test on Speedtest.net immediately after the upgrade to iOS 10.0.3 and got 102 Mbps. My highest download speed was on iOS 10.0.2 - 120 Mbps. Yesterday I upgraded from iOS 10.0.3 to iOS 10.1, and since the upgrade I haven't been able to get more than 60 Mbps down when checked on speediest.net. Today I ran the speed test on my wife's iPhone 6s Plus sitting right next to my iPhone 7. Both iPhones are on AT&T. My wife's iPhone 6s Plus consistently got download speeds that were about 25% higher than my iPhone 7. The iPhone 6s Plus is currently running iOS 10.0.2, whereas my iPhone 7 is now running iOS 10.1 (modem firmware 1.25.00; carrier update is AT&T 26.0). Prior to updating to iOS 10.1, I had the issue with the iPhone 7 switching from LTE to 4G, and the download speed dropping tenfold (to about 12 Mbps when on 4G). The iPhone 7 was on iOS 10.0.3 for only one day, so I'm not sure if 10.0.3 fixed the issue of random switching from LTE to 4G, but I know for sure that I was getting download speeds exceeding 100 Mbps on iOS 10.0.2 and 10.0.3. iOS 10.1 seems to have rectified the issue of random switching from LTE to 4G, but the download speed is only 50% of what it used to be on iOS 10.0.2 and 10.0.3. ------------- I ended up downgrading my iPhone 7 from iOS 10.1 to iOS 10.0.3 (yes, Apple is still signing 10.0.3 as of October 26 at 7:00 PM US Eastern Time). The iOS downgrade to 10.0.3 also downgraded the modem firmware from 1.25.00 to 1.00.05 and downgraded the carrier update from AT&T 26.0 to AT&T 25.0. My download speeds returned to pre-iOS 10.1 values, and speedtest.net run on iPhone 7 now consistently shows download speeds that are about 20% higher than those on my wife's iPhone 6s Plus running iOS 10.0.2. Whether Apple will admit this or not, iOS 10.1 degrades LTE download speed on iPhone 7 (Qaulcomm modem version of iPhone 7) when used with AT&T.