Okay in fairness, I'm sure these are great for some people! These are also my first nipple clamps, so I'm still figuring out which ones I like the most.
The tongs-style clamps are (for me) really difficult to attach, and I also struggle to get them to stay on through any real activity. I had better luck with the loop style ones, although they also slip off with a hard tug. Overall, difficult to attach, cute once on, not able to apply the pressure I was looking for.
That said, they are pretty affordable compared to others, so relatively low risk if you wanna try for the first time!