My now bicycle crazy nephew looked at my Mavic 851 SSC rear derailleur real close the other day and was befuddled by what he saw. He pointed out the two allen headed limit screws and asked me, "What are these two thingys that stick out for??" He knew they were for adjusting something, but indexing must have somehow minimized the role of limit screws on derailleurs at the lowest and highest rear cogs???
I remember that the limit screws were things that we always looked for and adjusted when we are presented with a new derrailleur we have not used before.
Resist it or not, unfortunately for some of us, the click it and forget it method of changing gears is pretty much the norm for biking these days, so don't be surprised if you get left behind in club rides more often because of slow shifts.

Chombi