I remember the times when it used to take 90 minutes to get a fill confirm back from places like Nymex Pits.
I remember people like Phil Flynn touting things like "Buy crude 44.65 with a 44.45 stop (that would have been stopped out, and with slippage before the entry fill confirm came back!)
I recall that LIMIT orders were loath to be taken by floor staff because such orders cannot be slipped. Many was the time the market would trade through my price, come way back again, and of course no fill because the idiot on the floor couldn't be bothered in the heat of the action with my single lot limit order.
CBOT pits on the other hand gave fairly quick fills, but would still slip you badly on stop orders using "the worst price of the last 5 minutes" system, that being around about the time it took for fills to come back.
Nowdays, pits seem to be used only for block orders (100 lots plus perhaps) as anyone with half a brain will just circumvent the entire thing by using the electronic dealing platforms instead.