I had the chance to try the PX7 S2 headphones at an audio store here in Sydney. I found when using them on my LGV30, the volume was way too low. Doesn't appear to be an option of increasing the volume in the Bowers app, as you can in the Sony app (I currently have WH-1000XM3 headphones).
I changed over to my iPhone & the volume was much improved, but still was over 3/4 of the way up to get to the volume I like listening at. Should add, I don't like my volume being ridiculously high.
John Darko has also done a video comparing the XM5 to these if anyone is interested.