It's not a chip but a sensor. The difference between 1/1.28'' and 1/1.14'' may not sound much but the whole tech of the IMX903 (double stacked CMOS for better light gathering, better video performance, cinematic mode) would make it way better. So it'd perform better at night (video especially), it'd have huger pixels & would allow Apple's 24mp mode to truly shine as it'd capture an amazing level of texture any time of the day, like this it just doesn't matter as much