When I had dough to burn I saw a few higher end indies, and the one common denominator was that things seemed to be less scripted. For some (like me), this was a plus. I didn't know what I'd get, but then, maybe neither did the girl until the "date" had progressed to a certain point.
This realization has only come after time has provided a little perspective. When I had less spending money and I started seeing lower end girls, I think I subconsciously adjusted my expectations and refused to see a difference. In retrospect, the lower end girls approached the dates in a more assembly line fashion. There was always the exception here and there, but usually those were girls who's looks or age (sorry for the crudeness) resulted in a necessity to compensate with superior performance.
Rarely have I ever felt cheated with a high end (by UG definition) girl, but there were many times I felt like I wasted $200-$300 after a session. I never paid over a thousand for an hour, so I can't speak to that issue. I never had to, though. I'm not interested in porn stars all that much. If I had the cash, I might spend it on Nikita Denise. Always had a thing for her.