This seems to confirm that the software is almost entirely the same, and that the very first iPhone 16 series phones which had been loaded with software in readiness to be shipped out for sale on September 20, had the earlier build which was superseded by the Sept. 16 build.

Apple appears to be internally testing iOS 18.0.1 for the iPhone, based on evidence of the software update in our website's analytics this

Instead of the Siri orb that you're used to, the edges of your iPhone screen glow with various colors when the assistant is listening to you. It's a welcome design change, even if Siri still doesn't have the anticipated Apple Intelligence features, but one aspect of the new Siri keeps annoying me.