I bought both the QC Ultra Earphones and Headphones. I returned the Earphones and kept the Headphones.
The Earphones randomly played static noise in the left channel, and the battery drained unevenly while idle. The build quality of the both the case and earphones was not up to par compared to the AirPods Pro. The difference in sound quality was not enough to justify giving up the seamless user experience of the AirPods Pro.
The Headphones are a marked improvement over the QC 35. The treble distortion is finally gone. I used the EQ to reduce the mids to -2 as electric guitars sounded too harsh. The bass is a bit excessive even with the built-in equal loudness compensation. The sound stage is narrow, but the overall frequency response and distortion are very good. The noise cancelling is excellent, but for a mild amount of cabin pressure. The clamping force is just right. I use it with the Creative BT-W5 USB dongle in aptX Adaptive Low Latency mode which brings down the latency to ~50 ms. In aptX Adaptive High Quality mode, the latency is 3x as long with poor lip sync.
Spatial audio sounds excellent, but it's incompatible with head-tracked Dolby Atmos on iOS / macOS. If you enable spatial audio on the QC Ultra while Dolby Atmos is enabled, you are incorrectly applying two HRTFs. In Still mode, spatial audio has head-tracking which works as well as the AirPods. In Motion mode, spatial audio does not stay firmly locked in the direction you're facing. If you turn your head quickly, the sound stage drifts to the side and snaps back after a short delay. On the AirPods, the sound stays firmly locked in the direction you're facing. The capacitive touch strip is unreliable and frequently results in unwanted volume changes when trying to make fine adjustments or trigger the long-press shortcut.
The yoke design puts even pressure around the ears unlike the AirPods Max's single-point attachment at the top which puts most of the pressure above the ear. The Focal Bathys has superior frquency response, dynamics, and sound stage, but the noise cancelling and user experince is lacking. The Focal Bathys also constantly crackled in aptX Adaptive Low Latency mode which made it unusable on PC. I would rather have a dedicated low latency work headphone like the Audeze Maxwell where passive isolation is enough, and a dedicated travel headphone like the QC Ultra with superior noise cancelling.
If you spend some time tuning the EQ, the QC Ultra is probably the best noise cancelling headphone overall, especially with aptX Adaptive Low Latency.