I have intensively compared the two cameras and their images (on a calibrated large monitor) and I am not a fanboy of any brand (no matter which one). The Xiaomi 15 Ultra definitely delivers better indoor pictures in less favourable lighting conditions compared to the Samsung. BUT: The two styles Leica Authentic and Leica Vibrant are both not designed to give you the most realistic colours possible. For example, my parquet floor is always shown in a completely wrong colour on the Xiaomi (if you only take pictures of landscapes outside, you won't notice this). The Xiaomi also has strong tendencies for overexposure which often leads to "wrong" pictures. You can adjust a lot via filters, but in this mode it has problems with strong light sources such as LED lights, sun, etc. The S25 Ultra is easier to adjust via the filters and you can achieve almost 100% true colour reproduction. But unfortunately there is a lot of noise and sometimes colour distortion indoors in poor lighting conditions. However, if you simply like the Leica style and don't particularly value pictures that are as close to reality as possible, but simply like "beautiful" pictures, you will love the Xiaomi camera. So since both have advantages and disadvantages, it depends on your personal needs.