I've had this issue from day one, right out of the box, I received the Mavic in December, it has never been crashed, I treat it like I treat my girlfriend.
I read couple of threads about it and the theory is that it can be fixed with a fw update, well, since then there have been 3 fw updates. The gimbal roll is not getting better, if anything, is getting worse. I have calibrated the Gimbal numerous time, specially right after an update, to no avail.
I did not want to send the aircraft back to DJI for warranty work because I do not want to deal with their customer service, not to mention I am not going to see it in a month.
This video was taken at the beginning of last month, since then 2 updates have been released and have applied them to the aircraft. As you can see the rolls were not that bad: