I have one and use it a lot. I bought it because my kids are XC skiers and their team has 4 of them, they wanted one at home and and my wife and I also wanted one.

I think it is great for swimming, you can hold the base of the handle between your thumb and index finger and get the same arm motion as a high elbow catch. I was also thinking about modifying a set of paddles to "latch" on to the handles which should not be too hard.

I have been mixing it into some strength sessions where I do the 500 M ski, then use the 1 minute recovery to do push ups, situps, squats. Its a killer workout. If you do good double poling technique it also works your abs, and there is a calf raise / small squat in each pull.