High end stuff has no limits, there's always a better system in some feature/property. Also, when you start to upgrade something, there's chance of endless loops (these speakers needs better amps, which shows some defects of my DAC, etc.)

So setting a limit, reaching it and leaving it there is good IMHO.

I run an entry level HiFi CD player with iPod interface through a vintage amplifier to a pair of bookshelf style speakers (which are pretty big for their class though).

If my friend is confusing whether his phone is ringing because a similar sound is present in the playing track, then it's good enough. Similarly, if you're enjoying the sound you're getting from your system, you've accomplished your goal IMHO.

I'm neither looking for loudness, nor for that ethereal sound. If I can hear everything in relatively clear manner, and I'm enjoying it, that's it. I'd rather enjoy it instead of sweating over smallest details.

For context: I used to play in orchestras.