BE WARNED: The Sony WH-1000XM4 are NOT rated for sports. I had a pair I used during lockdown for spin classes and they packed in completely - Sony couldn't fix them and said that they're not covered by warranty if they get wet (clearly you can't get sweaty with them without throwing away £300)!
In the interests of flagging what I (and other internet users) consider to be a glaring design flaw in these and their predecessors, the mx3, glaring enough to warrant not actually purchasing the product as a result, it is worth noting for anyone fastidious enough to make their way to the comments module of articles such as this that the outer plastic slider component that attaches the earpiece assembly to the headband and allows this to move up and down to account for different head sizes is extremely flimsy and is prone to snapping with a very limited amount of careful use (eg. on no more than twenty separate occasions while sitting at a seated desk over the lockdown period).
This plastic slider CANNOT be replaced without completely disassembling the entire right earpiece component which includes desoldering 10 microwires from the board housed inside this unit. The slider itself can also not be purchased from the manufacturer but has to be sourced via third party providers such as aliexpress where the best a user can hope for is a copy manufactured in china.
i do not care how good the sound quality in a noice cancelling headphone is if, quite frankly, i cannot use the thing after a year and a half because it will not remain on my head, and may cost me - should i agree to the prohibitive cost of repair specified by the manufacturer - £120 MINUS labour costs, in this case.
Waiting on delivery of my new QuietComfort 45s. I don't care if it is claimed that they are 'not as good' as these things. My QC I set are still my backup headphones and are going strong after seven years. I'll continue to vote with my wallet.