GHaFaS is very well suited to exploring the fine details of the internal kinematics of galaxies, as well as any phenomena related to the formation of high mass stars and their surroundings. It has been used to make the best measurements to date of the corotation radii of the density wave systems related to galaxy bars, and to explore the initial phases of the huge superbubbles caused by the combined stellar winds and supernovae of the OB associations of massive young stars, among a variety of its observing achievements.