(...) I have run into a problem with finding "better" items for my system. This is because my system(s) sound so good now with the Extreme that I don't really care about making the sound better it is so good now I am content with the way it is. (...)
Than you should be very happy with this situation. However such findings and happiness depend only on us and will last only how long we want them to last. Stereo is intrinsically an experimental evolutionary system, depending in large margin on our imagination to create an illusion. The fact that you have a long and large experience does not change anything on this fact. The point is that we stop when we want to stop, not when reach the non existing perfection of an unperfected system.
Being an audiophile is an hobby with many faces. One of them involves changes - in gear, room settings or even tweaks, but also a permanent search. When people say that the are "done", what is left?