That's the most "difficulty" thing to do.
Speakers taste are subjective, very much personal. For me speakers "X" could sound amazing, for you could sound not so bad or vice-versa.
I don't like very much of "hot" highs (B&W signature), probably, I've get used to it, since I've being listening B&W for 30 years. Also, I've felt a lack of "punch" bass. That's my experience with 602 S1.
However, the 606 S3 is widely known for being analytical, open, and full of energy, with a strong emphasis on high-resolution treble and clarity of detail. It's famous for focusing on a lively, revealing, and dynamic sound. I've never heard them before, tomorrow will be the first time.
I do like strong bass and not too brightness in highs, therefore, without sacrificing detail and refinement. That's why I´ve suggested the Monitor Audio Silver 100 7G. Also I've never heard them before.
About the KEF LS50, I see they placed in the middle of both (606 S3 and Silver 100), the most balanced speakers. Or I am wrong?