I'm not sure anyone here is answering Hubb's question. Skirting around issues yes as I have wondered the same thing.

My uneducated assessment is this.

As mentioned drag is a big factor. Several years ago, cheek cowls came out that could be added, this increased drag on the front end, therefor the plane set up the same(same engine, prop etc) as one without cowls would fly slower. In this example the wing loading would be essentially the same as cheek cowls weigh almost nothing.

Next, enter fixed gear. Again, added drag. Fly a plane with retracts with the gear down vs gear up and gear down will probably fly a little slower. May not be terribly noticeable but have seen retract servos break and large manuevers with the same plane more difficult to achieve due to the extra drag.

Next came the wide body style, Hyde Away, Smaragd, Partner. The Smaragd has a huge amount of frontal area, again drag. A corvette slips through the air a whole lot easier than a cab-over tractor trailer. Add bigger and thicker canopy and fixed gear this plane will fly slower than my Oly whose fuse is only 3" wide(guess)

So the next question is does throttle management make a plane fly slowly, WELL. I challenge this to say NO. Some designs are for some reason inherently happy flying fast. My OLY will not fly well slow. When I try to manage the throttle my level manuevers go from scores of 8-9's down to 5-6's because the plane doesn't like the slower speed. Everything from wing rocking to the wind having much more effect etc. This plane was 10lb 12oz with 77" wing with straight trailing edge. Am not aware of Sq" but don't think that was the culprit here.

My Oly Medal flies much slower with cheek cowls and is not as sensitive to slower flight problems. The span is 78" and the fuse is a little taller, otherwise they are almost the same. Haven't weighed it though.

Personally believe the design of the plane is key here and I am unable to guess why.

Lastly, we have bi-planes entering the mix now. If read correctly, Chip has said the leading edge of 2 wings is more frontal area than the leading edge of a monoplane, as well as the drag caused by the flying wires is why he gets same speed flight level, up down 45's. Or at least makes it more controllable.

These are my thoughts and certainly not studied but hope it helps.

ed