The Panasonic GH5 has been the camera darling of early 2017 for video enthusiasts and the addition of 120fps, 150fps and 180fps full HD was one of the most awaited features for the camera. Earlier footage showed a decrease in image quality when using higher frame rates on the camera and the appearance of moire and aliasing was evident. It was still far better than what the GH4s 96fps mode was able to do.
Recent new footage has re-examined the slow motion VFR mode and while there is a drop in quality the 180fps mode is still usable for many applications due to it retaining a lot of detail compared to other cameras. The image is loosing quite a lot of resolution in the vertical so it will not be true full HD when you compare with the up to 60fps mode.