Aging ears and Nuances

I am 77 years old.  I can't hear like I used to be able to, but like you, I can still hear some things.  My hearing extends out to 12-13 kHz, it varies a bit day to day.  In fact there is precious little music above 10 kHz, or even less.  It is really more a question of how disciplined you are in how you listen.

I’m 72,  I hear soundstage and instruments texture just fine. I gave up on listening to small differences in components years ago. It became completely unnecessary to enjoying the music. The advent of streaming has been  one my many joys in retirement. 
Rich

I am 73 and have found no reduction in my ability to characterize and discern nuances in high end systems. Overly trebly, hard and distorted high frequency bother me as much as ever.  

All the nuances of the midrange are still there. I know my high frequency hearing is not as good as it used to be, but my experience listening seems to have made up for it. When I listen with younger folks, our observations are the same as we compare notes. Also, high frequencies affect lower frequencies, so if you get them wrong the overall sound is negatively affected. 

I also get to listen to different systems... some of lower quality and some of higher quality... and of different character. The differences are instantly obvious.