total BS. a sound guy should work with you, not make the judgement of what he thinks you should sound like.
It's not about that. When you EQ your head you're shaping the sound coming from
your cabinet. And you need to let the sound dude shape the sound coming from
his cabinets. The EQ that works for your particular amp/cab combination will not sound the same through his amps/cabinets. That's why you should send him as much a flat signal as you can. A few small tweaks won't ruin anything, but that cool, scooped sound with a +18dB boost @ 40Hz that makes your trousers shake on stage will probably not sound right coming out of FOH. And instead of using the board-eq to make you sound awesome, he has to use it for damage control.
I agree that a soundguy should strive to make you sound like you, and being one myself, that's what I try to. Getting a somewhat flat signal makes this much easier. I'll listen to the sound coming from your amp, then try to replicate it on my board,
then make changes
if I have to, to make the bass blend nicely with the band.
A lot of people obsess over MY SOUND (and I'm one of them

), but between your fingers, your bass, your effects and your preamp (if I use the DI out on the head/Sansamp/similar), not including your three-band eq isn't going to severely ruin your sound.
EDIT: As for the original question: I'd give the sound tech as much as possible. Better signal-to-noise ratio. Ask the tech if he needs more or less during sound check and I'm sure you'll get an answer.
