Once you get there, the desire for larger aperture seems to be driven less by fever and dissatisfaction, and it is more a decision made with reason. Aperture can certainly make some challenges easier, but it also opens up new ones on the frontier of that aperture. I guess it's the desire for new challenges that justifies larger aperture, not so much disappointment with smaller ones.

Satisfaction versus Dissatisfaction . I've never upsized because i was dissatisfied with the views I was seeing . Rather , it was the combination of being satisfied along with opportunity.
In 2010, my wife and had purchased our high desert hideaway the previous year and I was having great fun with my refractors and my 12.5 inch and 16 inch Dobs .
It took a while as I had never thought about owning a 20 inch plus scope but I after a while , I realized that I was in an ideal situation to take advantage of a very large scope. Clear , reasonably dark skies, a large garage where the scope could be permanently left assembled, it seemed like a big scope would fit nicely .
So I decided to keep my eye open for a reasonably priced , large Dob . If one came along, that would be nice, if one didn't that was fine too.
One did .
For me, I spend enough time observing , last year about 160 nights last year for about 500 hours , that it does come down to the new challenges , pushing the limits. The showcase objects are great in a large scope but most of my time is spent on small , difficult objects , pushing the limits of perception .
Greg LeMond won the Tour de France 3 times. He once said ;
"It never gets any easier, you just go faster ."
I like that . In terms of large scopes , "It never gets any easier , the objects are just smaller and fainter .
Jon