I've never been a big fan of evening emh at future world and dhs.
At a busy time of year, Especially now that emh is only two hours- at regular park close test track, soarin and toy story may still have one hour lines- if it takes an hour to run through those people- then there is only one hour of "exclusive" touring. Epcot and dhs also don't have the number of attractions to spread out the crowds an most people will go for the few headliners.
World showcase during emh;however, is fantastic! I love Epcot at night and love extra hours in world showcase at night!