After testing everything extensively during this whole week for MANY hours, I´m glad that the huge step back that audioOS 15 was -particularly on the original homepods, but it also applies to the Minis to the extent that it can- is finally over.
Everything, for the first time in more than year (in my case, the performance and sound quality started deteriorating slowly after the release of audioOS 14.6, and went downhill with 15.0) remember me to the experience that I had with the original homepods when I first bought them.
First of all, everything is much faster, and I´m not talking about the usual sensation of improvement that we talk about sometimes after an update (myself included).
I´m convinced that Apple did something to the backend process of requesting data from Apple servers latency wise, because EVERY request (Apple Music songs, podcasts, radio stations...), is pretty much instantaneous now. Its unbelievable. This also applies to Homekit.
The new home app is fantastic, faster and a lot more reliable.
Lossless songs in particular now load as fast as their AAC counterparts. There is no buffering, no popping, no stopping at 15 seconds. Completely rock solid. This is also true of the IOS 16 music app, by the way.
Then there is the sound. First, Apple FINALLY restored the original maximum volume levels of the OG Homepod, which was capped around the release of 14.6 (maybe because of the overheating fiasco that killed many units around that time), and never cared to restore it in subsequent firmwares.
But it isnt just that. The detail of the bass, which is cleaner, is remarkable. The mids are no longer recessed, but louder and cleaner.
The highs are a little more prominent in the mix but not brittle. All in all, it just sound great. And if you use them with an Apple TV in home theater mode (make sure that you also update the Apple TV to tvOS 16), you are in for a treat.
Not only they are louder and fuller, but dialogue is much more clear and prominent without having to enable "reduce bass", which wasnt a solution because all that setting does is to remove sub bass.
Overall, a fantastic and long overdue update, IMHO. Just wanted to share it with the community because it was such a pleasant surprise.
PS: To avoid possible issues, make sure that you update your main IOS device (the one used to set up the pods) to IOS 16 before you update the Homepods themselves.