Tried 2.4.1 today on my 3DR Quad with stock motor and props, using parameter file for stock quad.
First flight was fine. Stabilize and Loiter working. After swapping battery and taking off the yaw started to drift clockwise at about 1 degree/second making it VERY hard to fly back to startingpoint from far away.
Loiter and RTL made the quad slowly drift away in some random direction.
The only thing that changed between the flights was a fresh battery. Same settings and starting point.