I bought mine specifically for use with vocals. It was for use into my four-track, as I wanted something that could do reverb and delay in one small box... did the job perfectly. Not sure about live use, though.
That's what I look for, in studio applications anyways... it was a big selling point for me with the DMM, since the software delays I used to use eat up all my processing power.
Reason being, I like to set the delay up as an insert on a delay send, and blend it in using a fader in ProTools, rather than going straight thru the box.
I use mine for vocals live for every show...it's perfect. I bought an XLR adapter so i can have it all set up and just run the stage mic cable to the pedal output. Yeah, you can turn the mix all the way up and the reverb all the way up. it's an amazing pedal, i want to buy another one so i can have two at once. seriously get it, you won't regret it.
at least i THINK you can get only a delay signal. now that i'm thinking about it, i can't remember. i never use it that way because the reverb is so nice.