I think with both types at their full potential, mated with compatible components the three way has the ability to deliver "more" music for your buck. The three-way is more revealing.
However, from the three-way speakers I've heard if they're not matched up with the right components they just reveal more of what I don't want to hear. Two-ways do sound more clear and crisp to my ears......but don't have as "big" of a sound as a three-way.
I heard some wonderful sounding, less efficient two-way speakers at the AudioKarma-Chicago get together. Very warm, inviting sounding two-ways but lacked the detail and articulate sound that Klipsch delivers. The Rega speakers they had there sure sounded nice though.....powered by a Fisher 400 tube receiver.