It's iOS smooth.
3 years ago I traded my iPhone 6s in for a 3T. While I loved the speed of the 3T, the ability to customize and tweak, custom fonts, custom icon packs, widgets galore, just superior in every aspect barring one! It didn't have the fluidity and smoothness of the 6s. It wasn't an almighty difference, just slight and noticeable.
Was it a deal breaker? Nope. I went on from the 3T to 5/5T/6 and now, for the last couple of months, the 7Pro.
That minute difference in fluidity and smoothness is no longer. I now compare the user experience to what I experience on my 120hz iPad Pro and the 7Pro is simply amazing! It is, by some margin, the most unique user experience I have ever experienced on a smart device.
It is an amazing device, with top end features, an absolute pleasure to use!!
If I had one wish it would be that OP ventured into the tablet market rather than smart TV's. I'd jump on it in a flash!! 855+ Snapdragon, 512gb rom/12gb ram, 11" QHD bezel less screen, 93% screen to body ratio, 320ppi, Android 10, 16MP front facing retractable camera, Gorilla glass 6 back and front, 90hz screen, dual speakers, dual sim card, 5G, 48MP main camera, 9000 mAh battery, all for around $850. Dammmmnnnnnn......