What the guy was talking about was being "short coupled". Different concept from control coupling.

the Citabria and Decathlon are, in fact, short coupled. Most acrobatic full scale aircraft are, as would be models of them. Pattern planes are very much NOT short coupled. RC trainers are usually not short coupled.

Ok, so what does it mean?

It means that the tail moment, the distance between the wing and the horizontal tail is "short".

How short is short? I'm sure someone with formal Aero engineering can exactly define it, but if you compare pictures the kinds of airplanes I mentioned above, you can get a pretty good idea pretty quickly.

So, here's the reason it's important. Short coupled airplanes tend to be very sensitive in pitch and yaw. A longer tail usually makes a plane more stable, and more "smooth" and fly a better "groove" in the air. That's why pattern planes have such long tails, it makes them fly smoother. Combine short couping with larger control deflections, and you get fast snaprolls and very quick acting controls. This can make a plane "twitchy" or even feel "unstable".

So, if you are a beginner, you want to avoid short coupled planes, like the Citabria or Decathlon. Also, compared to a typical RC trainer, a scale Cessnea 152 would almost be "short coupled" as well. Full scale planes have structural issues models don't, so it's easier to build a long, light, but strong tail to make the plane fly smoother.