I'm a fan of miniatures, i love it when everything's neat, tiny and precise, these tools did not satisfy me.
Yes, they are easy to use, they run smoothly and the holes are even. But, the holes they make are big, with ugly torn edges, it's ok if you sew with a thick thread or seed beads or twine, but if you need a delicate single-ply silk floss stitch - this tool will ruin your project. Absolutely not useable for paper piercing (as decorative holes).
Also you may need to apply extra power to pierce cardstock which causes wrinkles and messy look.
So I'm looking for some tool with finer needles.