I'm confused by some comments here too. Last gig I did a month or so back was with my Darkglass M900 head, with the drive circuit engaged as a key part of my sound. If I went pre-eq to FoH, FoH would have been getting a clean bass signal with no distortion. Why would I want to do that? Same would apply for any head with a real valve pre as well, being driven to give a distorted sound, if you go pre-eq none of this gets heard?
If you are heavily shaping your EQ to get the best out of a Cabinet, absolutely understand the need to go pre, but I very VERY rarely feel the need to do that, as ultimately the sound on-stage at the kind of gigs we do is just for me, punters only hear FoH PA.
Presume the Pre guys must be playing very clean?
On the other end of the spectrum, I also have the option (although restrict its use to recording at the moment) to send to FoH a cab simulated signal to mimic my cab being mic'd. I have done this a couple of times live and certainly had no complaints. I work hard to get my tone right, I wouldn't want a soundguy to change that to what he thinks is best as he is 9 times out of 10 not going to have a clue how I want to sit in the mix.