Of particular note are the four large suction cups on the bottom that make this seat really safe. If you set the seat into the already filled with bath water bath, can this still back and forth (for example, to bring the seat into place), but lifting is impossible without solving the Gumminäpfe. Also the child is relatively "deep" in this seat (our son is about 85 cm tall and the front edge gives him to just below the chest), so it also can not pass tilt over the edge. On the little toys at the front you could have done without any. Our son is interested in not sure, but he has also never hurt it. We had for our child so far also no towel put in the seat. The seat is roughened and provides at least for us for a sufficient grip.
The age of no more than about 16 months I think is an understatement. Our son is 18 months old and he has spread both in the legs as well as the body still plenty of space. Also - as mentioned above - it is securely and fairly deep in the seat When you have now not exceptionally large or "chubby" child, children are likely with age up to 2 years (maybe even a bit longer) loose in their place..
Certainly you should not leave the child alone still swim, but you can now relax with a book or similar next set and do not have to rigidly retain the child in mind all the time.
We would buy it again and again!