How many of us are truly satisfied with their systems?

There are more elements than just thee rig itself.  I once had a great man cave not any more.

Completely discontented. That's why I'm here reading this forum. 

Count me in twice.  Both my main system and my secondary system have been optimized so far as I am concerned and will remain so for the foreseeable future.

Elizabeth said it best. 
  If you’re an audiophile, you tweak, because you’re an audiophile.
If you didn’t tweak, you wouldn’t be an audiophile.

 It’s all in your head.

It is not easy to exhibit financial restraint when it comes to our hobbies or passions (in our case, music & audio). However, retirement or impending retirement will certainly force one to do so. If you are in that boat, I hope that after 40 - 50 years of trial and error, you've managed to find an audio system that you either love or can at least live with.