The most important word of advise?

Every component of every system is directly or indirectly susceptible to and greatly affected by dirty AC coming in from the street and uncontrolled resonance energy. Hence, I would suggest building your system around the best performing line conditioners and racking system you can find.

Both elements are by far the most misunderstood and least appreciated and are absolutely foundational to any system simply because you will never hear your system's true potential without these two items properly addressed. Regardless of what one currently owns.

-IMO

Build your system around speakers that rock your socks; match the speakers carefully with an amplifier. This is critical.

After that, buy components which please your ears not some reviewer, magazine, retailer, or thread poster.

Room treatment, room treatment, room treatment.

find someone you trust then just listen

I must agree with Stehno. 2 things brought my system to a level that I only read about before. I added the right power device (a regenerator) for my sources, and, I added the right (or at least closer to right) power cords. I have found that the quality or lack of quality of AC delivery to your sources and electronics is the key to feeding a higher quality signal to your speakers. Once a higher quality audio signal is sent to the speakers, and the speakers are good, then you have a more pure and beautiful sound. This is when you get the focus and individual placement of instruments in the soundstage, disappearance of the speakers, a widening and deepening of the soundstage that wraps around the speakers, greater imaging and separation, and the band playing in your room. These are concepts that I heard of for years but never experienced in my room until I experimented with plenty of power cords, and a regenerator. (already had quality ic's and sc's) If you can't do dedicated lines to help clean the ac, which was impractical for me, then a regenerator was the next best thing. And, do your due diligence with power cord auditioning until your system produces that magical illusion. There are other important issues to address. Amp-speaker matching and synergy are just as crucial.