When is your Hifi good enough?

Obsession has no limits, so the answer is obvious whether it is audio or anything else.
It is all pornography, in a manner of speaking.

A system is good enough for me (as for others who have said the same here and elsewhere) when I find myself completely absorbed, consumed, and inhabited by the music---becoming one with it, rather than thinking about the sound of it. Good equipment, and even good sound, is only the means to an end---more appreciation and enjoyment of, and deeper connection with, music---God's greatest gift to mankind (followed closely by dogs ;-). 

Amen.

My system has for the most part been good enough but it's like that guy who keeps banging his head on a wall: when asked why he does it, he replies that it feels so good when he stops.

All the best,
Nonoise

When You start listening to the music and simply enjoy it. When you stop obsessing and nit picking and or run out of money and come to your senses.  After realising you have spent more on equipment than your car.