First impressions are everything to a person in life. How you personally look, how you interact with people, how you sound, how your band looks and sounds. Most people do not get second chances at making a good 1st impression. But that 1st impression is likely to open up or pigeon hole everything you do.
My feelings are this: If this is a really important gig and it could lead to many other and more potentially lucrative gigs, I want to walk in looking and sounding like the second coming of (insert your fav artist here or yourself if you so choose)! Walking into a gig with speaker on a stick tells me, the gig isn't that critical to me, we can run sound from the stage, stick some dinero in the 'ol wallet and mosey on down the road. If I think a good reference from "Club Wango Tango" is going to get that gig I've been trying to get into at "Summerfesto", then maybe I should spend money to make money. Use the gig pay for quality production. Keep in mind there are a ton of out of work sound and light guys/companies right now that will cut good deals just to bring in some revenue while waiting for their next drywall job. I personally always want to look and sound my best which does require production. Altho if I just have an op for easy money, I'll do a speaker on a stick gig.
Now, that said, on to the dudes who want to bring in a vintage 80's PA with four subs per side and eight top boxes with eight wedges and a 40 channel FOH console and sixty four par 64's with a follow spot and a half dozen foggers: Get a grip. That is so stupid to haul all that crap into Guido's Tavern to play for a max crowd of 75-100 people. 1st off, Guido is scared sh*tless that "you-a gonn-a knock-a sometin-a off-a da walls." So if Guido has a so-so night but he's waiting until 5am to get your butts out of his club so he can lock up, go home, and be back at the bar at 9am? Get serious, you won't be back at Guido's! Your 1st impression was your last one here.
Take only in what you need, no matter what the idiot guitar player in your band says. I'm assuming because that's always been the bonehead I've worked with that insists on the "full show, it's already in the truck". Whether you are loud or not, you are perceived as being loud. Sure it is a stereotype to you, because you've mastered this taking 4 hours to set-up and 5 hours to tear down method of looking huge and sounding quiet. Even though you are the one in a million, the rest of the world don't work quite like that. Save your backs and your relationship with the talent buyer, leave the "full show" in the truck until you are playing a place that warrants the gear. A buddy of mine that runs FOH (on a laptop) for a major Country/Americana artist with a boat load of Top 40 hits, is running a single 15" D&B sub with three dual 8" two-ways in an array on pole mounts on the subs for audiences of up to 1,200 people and had gain to spare. It can be done with small gear. Just use big ears!
This may not get you more work, but it won't stop you from going back to play a club because you chased their regulars out with the threat of ridiculous volume. Outside of your buddy Leo who wants to hear "Slayer Man!", 98% of the audience want to be able to shoot the breeze while you are playing, pick up chicks or dudes, and have fun dancing to songs you don't want to be playing. They really don't go to see you at all. If they dig you, it was because you made a great 1st impression.
And nothing at all ruins a great gig like spending hours afterwards being a roadie, or watching half the band sit and drink while you are loading the truck.....already got the t-shirt...