Hi Andy
I don't think I've really used the brush enough for it to change hugely. Maybe it's broken in a bit more, but I think the biggest change has been down to me, partly to my improving lathering technique. I thought I was 'OK' at it prior to Christmas, but since then, combined with the experience I've gained from my (ever increasing!) variety of brushes and soaps.
I also adopted an "All or nothing" approach to using it, I really worked it into the soap, grinding it in quite hard, really working the bristles until they were really covered in a thick paste of lather. I think the brush respects this kind of more aggressive use.