Hi,
Not sure about the 450 but I can now tell you the difference on a 350. I only installed a two position switch that allows for "mild" (15k) and "wild" (6.8k).
In mild mode the throttle response is a lot smoother down low and the typical fuel injected "jerk" at the start of the throttle is noticeably less. Although only ridden once today it did seem to need less attention to stall in slow trials type stuff.
In the wild setting the idle speed jumps up and throttle was definitely jerky down low and very snappy, at low throttle it seemed edgy and wanted to "go now!"
However up the top end there seemed to be no discernible difference; both top ends rev out and power at the top end seemed to be the same. So for my Aus mapped 350 the main difference was down low.
Try it, my switch cost me $1.22 (50c switch, 12c for resistors and 60c for wire) See pic for switch wired onto handlebars ... to get the flat blades for the connector I doubled the copper and soldered it, then pinched it with pliers to flat and then trimmed it with very sharp mini side cutters until it fitted into the connector tightly. then heat shrink and all taped up.