Back in the day, Linn was all about synergy. Their components did actually sound better together. If you are looking for the best sound quality then that comes down mostly to the component design and the sound you are looking for. For example, some people prefer a more musical sound so not all amps and preamps are designed for that SQ. Some people prefer a more open, dynamic, and detailed sound. Most components are not designed to do both although I am sure to get responses that people have both. So the impedance matching s one thing to consider but there is more to it that just that.
Happy Listening.