I used panning in post processing.
Camera used was a Sony A7 90% of the time, with the city sequence done by D7000.
24MP gives a lot of room for panning
On the Sony A7 the milky way sequence was shot with Samyang 14mm F2.8 wide open others were with the kit lens. 28-70
On the D7000 I used a Tokina 11-16 2.8
If you are going full HD, and your final image after panning is around 3000 on the long side, you are okay. However, if you pan so much that your final image is 1080P, then its a problem