I have to say you are all wrong.
And then again, nobody is wrong.
There is no right and wrong, merely different perceptions.

The question often arises as to whether a scale model is flying at a realistic speed. So what is "Scale Speed"? I suppose most people would argue that it is the scale proportion of the speed of the full size aircraft. We might expect to see a fifth scale model flying at one fifth the speed of the full size.

For a model aircraft to fly at so called Scale Speed, so that it covers its own length in the same time as the full size, the weight of the full size is divided by the scale factor to the 4[SUP]th[/SUP] power. That will give a model weight which will satisfy our speed requirement in straight level flight. It would mean for example that a fifth scale aircraft should weigh the full size weight divided by 5x5x5x5 (5[SUP]4[/SUP]) or 625. That means that a Hurricane whose loaded weight was 7600 lb, when reduced to fifth scale (20%), should weigh 7600/625 or 12.16 lb. I will let you be the judge of how practical it may be to build and fly an 8 foot span Hurricane that weighs just 12 pounds.
However, for realistic scale flight in which the radius of turn of the model is the correct scale fraction of the radius of turn of the full size (at the same bank angle and angle of attack) we can say that the ratio of the weights must be as the cube of the Scale Factor. For the one fifth scale example again that means dividing the weight by 5[SUP]3[/SUP] or 125 so for our 20% scale Hurricane, scaling the weight by the cube rule would give an eight foot span model with a weight of 60.8 lb. The wing loading is up to 96 oz/sq.ft. The result is rather a heavy, fast flying, model which is smooth and realistic in manoeuvres.
The conclusion we are faced with, if you have been following me, is that there is no such thing as scale speed. It is completely impossible to satisfy two conflicting requirements. We could go for a very light model which will fly straight and level at "scale speed", but whose manoeuvres will be much too tight and unrealistic and will look “floaty”. Or we can have a heavy model which will fly realistic manoeuvres, but which will land much too fast.
Naturally a compromise is needed somewhere between those weights. This compromise will be a personal preference, and nobody can say that you are not flying to scale speed if your model weight is within the weight limits set by the cube and fourth power laws above. That's where the art and skill of scale model flying comes in. It is in finding just the right compromise which lets your model fly manoeuvres sufficiently smoothly without looking too fast when landing or flying straight and level.
It is a well acknowledged fact that big scale models fly better and more realistically. And it is not just the size itself that matters, but the scale factor. That is because the bigger the scale factor, the wider the gulf between the requirement for scale speed in straight flight and scale manoeuvres.

The above is quoted from a series of 4 articles I wrote in R/C Model World, from June through to August 2009.