On sale very important effect in delay history . Line 6 decided to shrink the DL4 tones to this one and added some options . So it has stereo inputs and outputs . It has tap tempo . The switch to decide if you want the delay to immediately go out or not . The advantage of this pedal is also the "mix" knob - in the middle the delay is as loud as the dry sound and moved to the right becomes louder than the dry sound . In normal delay like DD-3 you can't make the delay louder than dry sound.
One more thing - very rare in other pedals - You can set the tempo also when it is off by clicking softly (the light blinks in red colour ; you click twice to set the tempo).

Echo Park was still very popular few years before almost everyone stared copy their ideas . Those who prefer this "DL4-vibe" still use it . The list of the famous users of Echo Park includes :
Tim Pierce (Alice Cooper / Michael Jackson)
Dan Auerbach (The Black Keys)
Josh Klinghoffer (Red Hot Chili Peppers)
Serio Pizzorno (Kasabian)
Isaiah "Ikey" Owens (The Mars Volta / Jack White Band)
Elliot Easton (The Cars)
Gaz Coombes (Supergrass)
Stain Westerhus (Ulver)
Adrian Quesada (Black Pumas)
.. and many others

Anyway , mine works how it should . Two screws are missing underneath .