I'm pretty familiar with them too, and I see your point, but every time I've flown a plane with C/S prop controls, its had a retractable gear (about 5 years experience now - 12 total). As soon as I hit Vle, I'll throw the gear down, and get slowed much faster than if I pulled it all the way back to 14-15" from 23"/2300rpm. Constant speed props were designed to MINIMIZE drag in the cruise by increasing the angle of attack of the blade, thus showing a smaller cross-section to the relative wind. The only way you're going to get that drag back is to advance the propellor control and decrease the angle of attack (aka larger x-section), which gets really nasty (as you pointed out). On the flip side, if I'm in something with a FP prop, especially on an aircraft equipped with a climb prop, pull the power back and the airspeed instantly bleeds off, and in my experience, faster than the other. That said, I can't think of a fixed-pitch prop aircraft I've flown that had retractable gear, so it could have also been the fixed gear slowing me down as well (as in your case)... I'll get a pretty good demo of this next Tuesday. I'll be flying both types (fixed gear, fixed pitch prop vs retract/cs prop) back-to-back, so it should be interesting!