One problem with those two reviews is that they only cover what they are like straight out of the package. All strings change a bit over time, but Heartstrings are almost like two different strings in one.
They make me think of a nice pair of blue jeans. At first they are a bit stiff and rough, but over time they become soft and comfortable.
I haven’t had enough time in with the nylon “Whites” to compare, but a couple of the blends I’ve gotten some time into, have become nice and soft, and have mellowed out a bit on the whippyness. They still whip pretty fast, but are a bit slower and more controllable.
Like your jeans they may need a wash now and then. Mine were starting to not bind as well, and suspected they had gotten a bit oily. I just took a bit of hand soap and water, and rubbed them between my palms. Rinsed and dried, and they were binding great again! I’m getting a lot of millage out of them.
I loved them new, and i love them even more broken in!