People’s experiences do seem to vary. Either there are some slight differences in the hubs, people’s perceptions are different, the hubs respond different to different riding styles or some combination of these. The changes are also so gradual it’s hard to notice what changed when.
The one thing that is consistently reported is that they keep improving, at 15,000 miles mine runs as smooth a silk. The noise from 7 is still noticeable and gear 12 is considerably louder than anything else above 7, a shame as it’s often used.
I was advised to change oil after the first 1,000 miles and immediately noticed a difference, which I haven’t after later changes.