I just don't know what I would use them for. I don't think their versatile enough for me to include in a small kit. The heavier duty ones I've used ten to break around twenty pounds.

I agree, for shelter building they are quite usefull. Even better than cordage because they tighten up quicker. However they are harder to reuse and can't be used for much else.

If their small enough for a PSK then I think their too small.

Para cord will hold 550 pounds, can be used for rope, sewing etc. Zip ties do neither.

I do keep a couple hundred in the car and a couple hundrend in the house where siz and weight are not an issue.