Hatul
Contributor
I have the Gopro 9 and the 4. If you can do image stabilization in software, as I was doing with PowerDirector, you can get decent results with the 4. The 4 housing is better with its 3 button controls than the 9. The 9 has Custom Presets which are handy, a front facing viewfinder handy for selfies and a bigger rear viewfinder. The 9 touch screen is very finicky I find to use with my fat fingers. And of course the 9 does 4K 60fps videos which is what I use now. The 4K is handy for pulling stills.Since I am starting with a 4 black, sounds like it is a reason to update.
I use the 9 with Hypersmooth with Boost stabilization, but as I say I was getting good results with post-software stabilization on my PC with the Hero 4.
Also while debatable, with the 9 I don't use a red filter, just use Auto white balance and correct colors in software.