In terms of frequency response and distortion, Energy and Paradigm are clearly superior to Axiom. In general, Energy and Paradigm frequency response curves are much flatter and the distortion figures are much lower than Axiom's.
http://www.soundstagemagazine.com/speakermeasurements/

Axiom needs to flatten the frequency response and lower the distortion of its speakers to be more competitive with Energy and Paradigm.