Yeah, it was brand spanking new - 19 miles on the clock! I've now done about 1,400 miles and it has definitely eased off, but still occasionally noticeable. It's not having any other effect like feedback or pulling, so hopefully it is, as you say, just a bedding in issue! I had it in last week to look at another issue which was a clanking noise coming from the brake pedal when it was released (I'd posted this in another thread and someone said they had the same issue and got it fixed) - they admitted there was an issue and need a replacement part, so hopefully I'll get that fixed in the next week or two.
Other than that, it's running like a dream!