To mess up this whole situation, I must say that I like the contra (I have a Coda, but same difference) with my fretless. Granted, I don't play fretless that much anymore, nor do I play in a rock band, but I did play in a "Fusion" band. It was drums/bass/guitar trio with myself as the front-man, kinda. Lotsa bass melody tunes and such. It cut it for rehearsals, and when we got to venues I used the PA and monitors.
As people have said above, it does depend on the player and situations. Being a self proclaimed mainly upright bassist, I kinda like the "sterile" electric sound. But I'm trying to get a fairly uncolored "upright-esque" sound.