Actually bigger fly's better. A 1/4 scale cessna would probally be more stable then a .40 to .60 size cessna. Usually size is a money thing. Its not that bigger fly's harder, its that bigger cost more money! So if you have the money to invest in something like a 1/4 scale cessna rather than a .40 -.60 size cessna, then in reality you will be getting the more stable, visually slower, and easier to see Aircraft.