just gonna have to say it now. if you expect an amazing experience with the hifi audio, you're probably gonna have a bad time. you'll need an external DAC and a high quality audiophile level headphone to even have the possibility of hearing the better quality. neither of these things are provided by Apple. your entry level option is to go buy a Sennheiser HD6XX, Schiit Modi, and Schiit Magni, but this will already set you back $420 (plux tax).
i don't wanna be that guy to say "steve jobs would've blah blah blah", but steve jobs probably wouldn't bother with the hifi business because of the clunkiness of needing an external amp, dac, and headphone that isn't sold by Apple. not only that, steve jobs cares more about the user experience than the technical specs. 90% of you guys will probably not be able to tell the difference between 256 AAC and ALAC.
now spatial audio might be decent, but it's not even one of Apple's tech.