I guess for me, my focus is on the figure - anything else to me is a waste of time (and I get very little painting time). I buy a cheaper brush that in the end lasts longer, requires much less maintenance, and for me anyway I get the same result at the end of the day. So for me, I don't feel the need to use Series 7's-not to say no one should, but I personally don't.
I guess for me a car analogy would be good. A Ferrarri is a fine and beautiful autmobile, they are fast, impressive but require to be tuned regularly. If my goal is to be fast and impressive, then a Ferrarri is my car, if my goal is to get to work every day then the last thing I want to do is have to tune my car once a week.
It's also my experience that they lose their points quickly, could just be I don't take care of them enough.