Been to one, not really my thing. Kind of boring since I like the visuals, and likely because I'm very familiar with basic haunted house tricks and such. Mostly just screaming or loud bangs/noises, and feeling things like webbing or the air ticklers at ankle level, and the did have a wonky walkway that was pretty funky to walk across (had handrails but still difficult to do in the dark). Oh, and there were some folks that kept getting out their phones and lighting up areas, so if you have anyone go through a total blackout, they'll likely just cheat with their phones anyway defeating the whole theme...
Low light situations are nice tho. They did have a few pockets of extremely weak light, which heightened the tension/expectation of a scare happening in the area.
Disadvantages I could see would be folks tripping/falling/bumping hard into things and either hurting themselves or damaging your props/scenes if they get disorientated or scared. So I'd worry about getting sued if this was a home haunt and allowing strangers to come through.