I don’t expect a $30 cam to match a $100 camera for quality, but if they advertise 4K they should AT LEAST get something close, not … this … mess …
My recommendation, if you’re looking at an Allwinner camera, is to stay vigilant and read the specs very carefully so you don’t get ripped off. The V3 is bundled with one of two image sensors: an OV4689, which has the best image quality out of the box despite only being 4MP, or an IMX179 which is 8MP and generally has more mediocre image quality. The V3S on the other hand is being bundled with one of two sensors: a GC2023, which is 2MP, and not even high enough resolution for 1080p let alone 4K, or the OV2720 which is also 2MP but can do 1080p resolution. At the price point of these cameras, it’s worth spending the extra $10 – $20 to get something with far more capable specs instead of cheaping out.