I've never used one, but the principle is the same. Bigger aperture and ferrites increase the sensitivity to the magnetic field component of the signal, ferrites just use less physical space. A bigger aperture also increases the footprint that can 'see' the electrical component better. Folks that use HF wire loops deal with this all the time. Sometimes you just don't have the real estate to make a circle or square with the full-wave wire, and just fit it in however. But there's a noticeable difference when you get to spread one out properly.
