Hey All, 
 Way back in the day I used to get two path echo at times, particularly on Asian stations  (ie on  R. Japan FROM Japanese soil)  -probably via Polar path and another route at the same time. I thought it was SOOO cool. Some of  my  ultimate Dx was "polished off" with an echo. If heard that effect , I knew it was from FAR away ! 
The other type of echo I have gotten at times ( heard it lately) is network programming being fed to two MW stations on the same frequency. "Interesting" , but not NEARLY  as "mysterious" or "romantic" as a long haul dx  HF    echoed sky wave  .
K