The DLE 20 goes to full advance in a single leap, down closer to 2500 rpm. That's the basis of the issue with it if there is one, noticed more often on it's way down as it retards. The standard Rcexl module, like the one used on the 55, does it in a few steps, a REAL curve, not a single step/on-off switch kind of thing, and it does it at a higher rpm where the chances of it being noticable are slim to none. Not sure what rpm that one's "all in" at. Could be the 4500 your thinking, dunno. -Al