Once in a while I've jammed (as opposed to performed) with a solid body electric to accompany my voice. For me it comes down to volume level relative to my voice (and other instruments), and tone. I prefer a clean signal with perhaps a touch of chorus and/or reverb, just enough to fatten the tone a bit without obvious modulation in order to emulate an acoustic in the room. It's handy to be able to goose the volume a bit for solos too.