
DJI
Osmo Action 5 Pro
Great low-light, mic integration; watch out for lens flare.

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I've had * Hero 3 White * Hero 4 Silver * Hero 7 Black * Max (1) * Hero 12 Black and I still have all but the 3 white. The 3 white was the only 'bad' one I think, one where the camera really didn't live up to the hype for me and hence I upgraded quite quickly. As for my favourite? In the context of when they came out the 7 felt the most incredible, it really was a big jump with the stabilisation. But I probably shot most of my coolest footage on either the 4 Silver or the Max, just because of the time in my life I was using them and the novelty of 360 footage at the time.
If you're on a budget I think everything past the Hero 7 black has had really usable video as that was the first model with the hypersmooth stabilisation which made a big difference. Definitely improvements have been made but footage from the 7 very much holds up. I would err on the side of getting a full fat "Hero X Black" model and just go older to fit your budget, as these tend to have the better support and reliability and replaceable batteries when some of the budget models have missed out on features like replaceable batteries and front and even sometimes rear screens Absolute lowest end of budget I'd recommend would be hero 4 silver. The rear screen makes such a difference to getting your shots right and it still has all the essential features that make a GoPro what they are. You can pick one up for a fraction of the cost of the top end models (£50 vs £250-350).
Enjoy! I remember my first action cam, the SJCam and onto Hero 4 Silver. I ended up capturing memorable moments in my life. Creating and sharing content is good but just capturing footage for your own collection is priceless. Get out there and capture everything!
You'll find a big improvement between a Hero 4 and an Osmo 6.
I filmed my wedding with a couple gopros. They were 4s back in 2015. My only recommendation is don’t film a wedding using GoPros. But if you absolutely want to I bet the 13 with that anamorphic lens could get some good shots.
I’ve had 3 different generations (4,8,10 IINM). My main headache was reliable charging (bad contact, I guess), and starting. Thinking it should be all charged and have it die shortly or not start was super annoying. It could work great, or fail. I’m still getting used to trusting it, since it seems to be behaving.
It will work. All depends on your personal definition of "good images." Get the 6 and an underwater case and shoot away. Or just turn on video and take screen grabs. I have several underwater cameras and still use a GP4 on my airplane. Each iteration of GP adds features, so moving to 7 or 11 will be better. But the 6 will take decent images. All depends on your budget and what is "good" enough for you.

DJI
Osmo Action 5 Pro
Great low-light, mic integration; watch out for lens flare.

DJI
Osmo Action 4
Reliable, stable, good battery; struggles in low light.

Insta360
Ace Pro 2
Community favorite for low-light, 8K; lacks 10-bit color.

Insta360
Insta360 X5
Replaceable lenses, 360 reframing; poor distant image quality.

DJI
Osmo Action 6
Strong low-light, good battery; aggressive HDR, soft night photos.

Ranked #1
DJI - Osmo Action 5 Pro

Ranked #1
DJI - Osmo Action 5 Pro

Ranked #1
DJI - Osmo Action 4

Ranked #1
DJI - Osmo Action 5 Pro

Ranked #1
DJI - Osmo Action 4

Ranked #1
DJI - Osmo Action 5 Pro