I have the Pomona Kelvin probes, and a set of Kevlin clips as well. The probes are a lot more convenient, I and are far better than standard 2-wire test leads if your meter supports 4-wire ohms.
I would say I have good experience with the Pomona Kelvin probes down to the mid or low tens of milliohms, but if you need milliohm accuracy, you need the clips or 4 wires. Note that if you end up measuring odd-shaped things like PCB traces, you might not be able to position the clips for a measurement.
BTW, had no issues with the Pomona probe quality, but maybe I got a good set. But if they fail, I'll use the leads and make my own tips. The concept is pretty simply.
John