I also own the XM4 and last month I bought the XM5. Is it worthy? If you are happy with the ones you have, it is a question of spending money. I liked, what you have mentioned, being smaller, less obtrusive and I believe have a better ANC.

For me, the most important thing was the smaller size of the xm5 headphones. I also had the xm4, which I found too big and too visible, the xm5 is more discreet. Otherwise, no spectacular progress in terms of sound, perhaps better noise-cancelling.

Hi buempliz.casablanca,

the special Dynamic Driver X driver unit provides wide frequency response, enabling deeper bass, fine vocals and higher detail, especially for high-frequency instruments.
With these headphones, you can have Sony's best call quality yet.
Thanks to an AI-based noise reduction algorithm via a Deep Neural Network (DNN) as well as bone conduction sensors, your voice will be reproduced clearly and naturally even in a noisy environment. Outdoors, the noise-canceling design minimises wind noise so you're always heard.
You can find out more about the functions on our support page.

Sony Europe

If you are happy with your xm4 so far, it doesn't make sense to change. I would rather wait for another generation to change, because then it will have more/other advances or improvements for which a change would make more sense.