I usually prefer lighter-bar/faster setup.
Sometime I try new tricks and want the kite slower, I just grab the bar closer to the center. Obiviously the oposite is not possible : to be on the slow turning setup and to grab wider than the bar to make if faster.
In strong winds, on smaller kites (5-7m), I use to prefer slower setup. On smaller kites, higher bar preasure is not a problem.