HI Keith,
Right now, I haven't got a Line 6 DL4 at all - mine broke, and I've not got round to replacing it yet. When the Echoplex guys upgraded their software to loop IV they added a double speed/half speed function to it so it did everything I needed it to do. The thing I actually miss most on the DL4 is the sweep echo - I was listening to 'Conversations' the other evening (my album with pianist Jez Carr) and there's a track on there that begins with a long bass intro through the sweep echo, and I miss not being able to do that...
Anyway - for looping I now primarily use two Echoplexes - I've got four of them, but rarely hook them all up. I also use my Lexicon MPX-G2 for some looping, as it's got 20 secs of loop time in it, and occasionally loop a phrase into my Korg Kaoss II, which I guess is technically more of a sample player than a looper in that you sample and then retrigger, rather than play and loop in real time...
Of all the loopers I've ever tried or seen demo'd, the echoplex wins hands down. More functions, easier to use, intuitive interface, single unit rack mount - everything about it is cool (though they can be slightly tempramental - I guess that's the 1980s macintosh processor technology that powers them!!) It's got three minutes of loop time, but no storage function. For storage, I use either minidisc or PC...
If you want a looper that stores, you're best bet is probably the Repeater, though it's discontinued so you might struggle to find one. Either that or the RC-20, but that's fairly limited in terms of what it will do.
So my vote goes to the Echoplex - though it sounds like the Digitech thingie with the multitrack recording function might be cool too - I've no idea how useable in a gig setting it is, but probably worth checking out...
Steve
www.stevelawson.net
a question for steve 
