The chromes are pretty stiff, but maybe the fenders are stiffer? I'm pretty sure the fenders are lower tension, just because of adjusting the truss rod, but I know stiffness isn't equal to tension. I think both are pretty bright out of the box, but like all strings, they calm down. Probably faster for me, since I kill strings really fast (Elixirs are my main string). Maybe what you noticed was the same as I did, that after the brightness wears off there is still a little grind of some sort with the fenders. I can see a person who likes flats not liking that, for sure.