We had used a different model/brand before over the years which had one advantage over these: a cord inside the tubing to prevent a breaking cord from snapping against a swimmer. I have also used this type of cord before and found it greatly outlasted the other brand, by several seasons, and before finally breaking showed obvious signs of deterioration so we could stop using it before an accidental break. I find this cord material much easier to use, fewer kinks and knots, easier to clean, dry out, and store. The adjustable tensioner is new to me, seems of dubious value due to a limited range, and frankly, in use, another swimmer helps keep tension on the belt to increase the range over which it is active. And the tension seems appropriate for our 25 yd pool.
Kids had no problems figuring out the belt, which may sound odd as it seems so simple, but in the past, with other belts, the statement, "it just fastens like a seatbelt" only showed my age as they were only familiar with metal clip seatbelts.
Summay: working well, I would prefer these again over other options.