720p/60 on the P2v+v3 looked very good. I cant see 1080p/60 looking worse. I believe the P3A and the P3P cameras are phycially the same just different software.
Does it mention anywhere what each camera's video bitrate for each recording is? That might determine the video quality difference between the GoPro and the P3 cameras. Resolution and frame rate is one thing, but bitrate is another.