Strictly speaking, I don't think these things have a 'size' with a border where you can be inside or outside of a lepton 'surface'. Its a basically a point source with a field effect as far as we can determine. http://en.wikipedia.org/wiki/Classical_electron_radius

I think the article is saying that the field affect appears to be completely uniform.

Technically, if the electron can affect something at a great distance via gravity or releasing photons you could say the size of an electron is many light years in diameter. Or you could call it infinitesimally tiny.

Neutrons and protons we know to be complicated little parties of quarks and gluons, each of which are, as far as we know, are also elementary particles like leptons.