I'd skip the gopro. I have one. It's an expensive paper weight. Video quality from your old cell phone is probably better. Just buy a few mounts for the spare cell phone you probably have laying around and us it. Way more features, better video, and everyone has a few laying around. If you have a samsung you can link to your current phone for remote view and control and use it like a gopro.
For better video - mirrorless camera.
Unless you really need the small size for something - I would carefully consider whether a gopro is worth the $.
As a side note - I have a DJI Phantom - and the video quality is fantastic. BUT - unless you only want to use it around your car - wait for a good deal on a Mavic Pro. The size is a killer on the Phantom. It's just too bulky for casual use. I regret choosing the Phantom every time I use it.
Just my .02.