Originally Posted by JanMM

Just the opposite of my experience - had to get a Park masterlink tool when I started using KMC chains/masterlinks after years of no problems with SRAM.

Have never had a masterlink of either brand fail but in recent years have given spare KMC masterlinks to two tandem teams stranded on the roadside by masterlink failures - don't know what brands.
I always carry a couple of the KMC ones - bought a bunch of them on Amazon.