Now Randy. Shame on you. 
That wasn't what I said.
I sort of disagree with your contention that profiles are inherently inferior fliers but you are absolutely correct that the "standard" profile layout suffers from rigidity problems that make them susceptible to degradation in performance that has little to do with their airworthiness. All of my profile designs have done something to reduce exposure to those problem...primarily with respect to firming up the front end to provide better engine runs which is probably much more important than any possible aerodynamic shortcomings profiles might have. I think the attention being paid to firming up the aft fuselage (particularly on modern length tails) has merit as well.
If, however, rigidity and maximized engine performance issues are properly addressed I can think of nothing about a simple fuse with the "stuff" hanging out all over it that makes one irredeemably handicapped. The primary thing from an aerodynamic standpoint that differentiates a profile from a well designed and executed built up fuse is the drag that results from all the "stuff" hanging out in the breeze. One of the tenets with which I'm in full agreement with Al Rabe is that form drag on a stunt ship isn't an altogether bad thing. First because we don't need to fly at speeds that demand minimization of drag and second that some form drag (as opposed to high induced drag from inefficient lifting surfaces that can compromise speed control in maneuvers) really helps control speed and to some degree allows the use of greater thrust without excessive airspeed which can benefit us by virtue of improved speed consistency.
The things to which I attributed the Imitation's wonderful handling qualities were the relatively high aspect ratio wing, the longer and larger tail and the small chord flaps (15% of the chord at all stations) which reduced hinge loads and allowed a light touch on the handle. The original was a very predictable flier than didn't require any significant amount of practice to fly well and was very forgiving of trim variations. A ton of Imitation derivatives were built in the Bay Area with built up fuses taken more or less directly from the plans for the Excitation which was based on the Imitation aerodynamic ideas and profile view but used a more tapered wing with swept forward hingelines. The hermaphrodite versions simply put the better handling Imitation wing in the Excitation fuse with a tiny adjustment to the wing cut-out to place the MAC in the proper place. David Fitz, for example, built at least two (and I think three) of these that he flew with some success at Nats and team trials.
The bottom line vis a vis profile versus built up stunters is that serious stunt fliers want serious looking airplanes and, frankly, need them to optimize the handicapping that precedes flight--i.e. appearance points. There is also the questionable concern about impression points from the judges--a subject into which I prefer not to venture 
.
Ted
Now shame on you Ted...I didn't really say the profiles were inherently inferior fliers, I said that they were structually inferior and that it was nearly impossible to make the fuselage stiff enough to be the equal of the built up version.
At any rate my statement was meant as an infusion of a bit of levity. Nearly everyone in the thread has taken the opposite argument to my original statements and many came to conclusions about those statements that do not necessarily follow logic.
Some have discussed going to great lengths to make the fuselage stiffer. Most of those completely over ride any advantage to building a profile in the first place. Most would also be likely to actually build heavier than a similar built up fuselage which would most likely still be somewhat stiffer.
The original question was can a profile stunter with flaps fly as well as a built up stunter with flaps.
I assumed that in order to honestly answer that question one must consider everything except the profile fuselage to be on an equal aerodynamic status, excepting for the increased drag, which I also do not think is really an issue. I also assumed that the gentleman asking the question didn't want any special consideration placed on it like...well it's fine if you're only a sport flier, or it will work just as well if you don't try to fly it in high winds.
A Stabilizer is supposed to do just that...stabilize. If it is twisting one way on the up wind side of the circle and the other on the downwind side of the circle, as I have actually witnessed some do, it really isn't doing it's intended job. if it flexes back and forth in turbulent air caused by prop wake, not only torsionally but laterally also, as I have actually witnessed, it isn't doing it's intended job.
The imitation is in my opinion a very good flying airplane. I contribute that to truly superior aerodynamic design. I have flown two different ones belonging to OP and one flew very well. The other was in bad need of some trimming (it also had sticky controls) to make it competitive or easier to fly, but the owner couldn't be convinced of that. As an intermediate level flier he thought it was fine for him.
I didn't fly either of them in contest typical afternoon wind but am willing to take your word if you say they will deal with wind.
Nearly all of the other profiles I've flown including my own with all the geodetic and carbon fiber tricks...didn't. That's not to say they couldn't be flown in wind just that they were quirky and less precise. That's especially true in dead calm conditions where prop wake is prevalent.
So...if the airplanes are considered aerodynamically equal but one is structurally inferior to the other, my conclusion remains that under at least some conditions the structurally inferior one will be at a disadvantage.
I would agree with Tim Wescott that all the stiffening tricks to make the profile fuselage stiff does infringe on it's main advantage of being simple and easy to repair.
Given that, the question looms...Why build one if you are looking for the BEST flier!
Randy Cuberly
PS: I really enjoyed your rendition of the National Anthem in the other thread.
I envy you because as an "Old tired Guy" I'm not doing much singing anymore.
Topic: A Flapped Profile vs. A flapped built up fuselage (Read 10795 times)