I just recently switched over to the new Boss RE-20 Space Echo specifically for the rockabilly slapback echo sound. For years I used (and still own) the Line 6,DL-4 not for the most ideal slap back echo but for its versatility and three pre-sets. Different band: afro-cuban & reggae music lends itself for lots of different echo's. However I am now playing in a three piece: rockabilly, surf, r&b kind of group (I play a Gretsch into a Vox AC-15 and/or old Fender Pro and I crank the reverb). So with that vibe in mind, I switched over to the Boss because I can hear an improvement in getting that tape echo like sound. I owned an non-tube echoplex and a Guild Wildcat? tape echo years ago. Without going back to a tape based machine, does anyone think there is a better pedal out there? On a side bar, I wished the Boss had pre-sets like the Line 6 did. I found them quite handy.