I have listened extensively to both the Carrera and the Carbon 7 mk II and they're both lovely speakers. I cannot recall about the "low listening" element.
However, your question raises another one for me, namely,
"Don't speakers perform differently at low levels depending on the amplifier driving them?"
If the answer to that question is "yes" than without knowing which amplifiers people are using to drive the Fritz, I'm not sure you're collecting useful information.