Sure do. 10.3.2 and it’s great. Also have a 6S Plus on 14.2 so I know a before and after for 3D Touch on the phones not being the same post 12 or so. Have a pair of iPhone 5s on 7.1.2 so pretty well covered for generations of the OS/Hardware.
Amazing! Funnily enough, I have almost the same! The 3D Touch thing is really amazing on iOS 10! I’m on iOS 10.0, which is interesting, because it is pre-battery throttle for the iPhone 6s (added on iOS 10.2.1). On 3D Touch, I have an iPhone 6s on iOS 13.4, and the difference is significant, they’ve really degraded the experience after iOS 13 (they added Haptic Touch there, with the iPhone 11, which killed 3D Touch). I also have an iPhone 5s running iOS 8.2! How amazing it is that you have them on iOS 7!
Unfortunately, for me to go to a combo in which the iPhone was released with that iOS version I’d have to go to my main phone: the Xʀ running iOS 12. I don’t have the 5s on iOS 7 because I bought it late and it came with iOS 8.2 installed. My 6s on iOS 13 was my favourite iPhone ever back when it was on iOS 9, but it was forced out due to the iOS 9 on the A9 activation bug, in which that combo of iOS/processor would deactivate: it affected my A9X-powered 9.7-inch iPad Pro too, which was on iOS 9 until 2019, when Apple forced it into iOS 12. It is still there today! In fact, I’m writing this from it. So I went from an A9 combo of iPhone/iPad on iOS 9, to iOS 10 and 12, respectively. Not perfect, but not too bad, right?
That A9 on iOS 9 combo was my most cherished, though. I’d love to have it. But like I said elsewhere, the iPhone 6s on iOS 13 isn’t used anymore (I have one on iOS 10, so not too appealing, honestly), and the iPad, while not perfect on iOS 12, could be a lot worse. Glass half-full: at least it was forced out on iOS 12 and not on iPadOS 16. Again, even if not perfect, iOS 10/12 >>> iOS 15/iPadOS 16.
I have a little gem: an iPod Touch 5G running iOS 6.0, the first version ever released for it.