And it’s a pain to change tanks with weight on the cam band.1) It sits even lower than on the cam band, thus more leverage for maximum trimming effect with the smallest weight.
2) The weights sit flat on the backplate while in trim and stable, compared to on the band which is higher and induces rotation and instability.
3) I don't like things, esp weights, hanging out of the cam band. This is sleeker, in the slip stream, and reduces drag.