  Since 2002, the number of detected blazars at E_\gamma > 100 GeV has more
than doubled. I study all currently known BL Lac-type objects with published
energy spectra. Their intrinsic energy spectra are reconstructed by removing
extragalactic background light attenuation effects. The emission properties are
then compared and correlated among each other, with X-ray data, and with the
individual black hole masses. In addition, I consider temporal properties of
the very high energy gamma-ray flux. Key findings concern the flux--black hole
mass and variability scale--black hole mass connections and the correlation of
the spectral slope and the luminosity. As a specific application, the study
allows to constrain the still undetermined redshift of the blazar PG 1553+113.
