worth it

Hi All, New to the forum and wondering if I can get some help. I've already got a DDPai M6 camera mount to the front windscreen of my Astra K 1.6T and was wondering if it would be worthwhile getting another camera to fit to the rear windscreen. Been watching some dashcam footage videos on...

So as you may have noticed, the big brother of our favourite camera came out some time ago. So I was wondering if it is really worth upgrading or if I should stick with my Yi 1. Can anyone tell me how big the quality difference is ( especially in 1080p since I won't be 4k too much) Thx for your...