When is your system good enough-and why?

Frank van Alstine once suggested that this should be measured by how much time you actually spent listening to your system (not Frank's exact words, but my summary). When the sense of pleasure of the "rightness of the sound" is added, I agree it is an excellent yardstick. I have traded many systems that gave me great pleasure for more capable ones that did not. My listening time invariably plummeted.
Many have replaced tube based systems that were wonderful at low volume but failed at so called "realistic" volumes or with demanding material, with solid state replacements did the demanding material, but never delivered the pleasure of it's predecessor. I wandered about for years before discovering some of the particular characteristics that made all the difference to me (tubes, surprisingly were not among them). Rather than recite my list (and perhaps have to defend it), I would like to take the coward's way out and ask others what they have discovered matters to them sufficiently to make their system "good enough".