I've only been using these scales for a week and so far so good. I have found the app a little tricky to use and so far can't seem to use all the promised bells and whistles and am only shown BMI and weight. But, I feel this is more due to me not spending the time to learn how to use the app and not an actual issue or fault with the scales or apps.
Being a tall person with big feet, I do find the size of the scales a little intimidating - as they seem so small and delicate. But, saying that, I can stand on them fine, if not a little gently (they are so small compared to my old scales) and they can weigh me without issue. It's good they weigh up to 180kg... I'm not actually THAT heavy, but knowing they can take up to that weight makes me feel more confident stepping on such tiny, thin scales. So, please don't be concerned by their size and weight. They really do come across as being to small, light, and thin to be of any use... and yet they work amazingly well and am very happy to have purchased them.