How does it compare with the Sony WH-1000XM5?

Both have excellent noise cancelling. The Bose adds Immersive Audio spatial sound and a more padded fit; the Sony has a lighter build and more detailed app EQ. Choice comes down to whether you want spatial audio or a lighter headset.

Is Immersive Audio worth using?

It widens the soundstage and tracks head movement, which suits films and live recordings. It uses more battery, so many owners switch it off for commuting and on for movies.

Yes, with the included audio cable, so it works on in-flight entertainment and studio gear. Noise cancelling still runs in wired mode when the headphones are powered on.

How long does the battery last?

Bose rates roughly a full day of listening with cancellation on, less with Immersive Audio enabled. Fast charging gives hours of playback from a short charge.

Does it work with Android and iPhone?

Yes, it pairs over Bluetooth with both, and the Bose app handles firmware, EQ and mode settings on either platform. Multipoint lets it stay connected to two devices at once.

Is it a big step up from the QuietComfort 45?

Yes on cancellation and features: the Ultra adds Immersive Audio, a better Aware mode and improved mics. The 45 remains lighter and simpler if you don't need spatial sound.