thoughts on PTC resettable fuses to protect USB port

I always find this confusing, don't think I've ordered the same thing twice.

Do we go with a low ohm part that will Hold at 500mA and trip at something higher? Or hold lower, like 250mA, and trip closer to 500mA?

Hold 500mA, trip at 1A

Hold 350mA, trip at 700mA

Hold 250mA, trip at 500mA