I pretty much agree with what has been said but also I feel the plane is a factor at the top level. Into this comes how the plane is setup and the ability of the pilot. If two pilots had equal ability and one was flying a 2m top of the line airframe while the other was flying a 60 sized sport plane then the 2m would surely win the competition. I think the skill comes into play when a more highly skilled pilot flys the smaller 60 sized plane and beats the top of the line plane, has the pilot of the 60 sized plane needed to practice more? I think so. Surely the better plane has an advantage and skill and practice cannot be the only thing when planes are so different. Because 35% and 40% aircraft fly pretty much the same An extreme example shows this better: Why doesn't a TOC pilot fly a 60 sized extra at the TOC?? Because bigger flies better, maneuvers are easier and the maneuvers are slower.... So this means a bigger plane gives an advantage but for the average Jo Bloggs my opinion is that a specialized better flying well setup plane will give an advantage if flying against lesser planes.... From this you can give other things which will help, top of the line servos such as digital which are more precise, more reliable motors, eg (efi) and new composite light weight airframes which give a lower wing loading and fly better. This has got to affect the result's somewhat.