I have the broad extreme of eaters here. Daisy eats fast and furious. I saw her eat a whole egg the other day just swallowing it- she didn't even bite it to break it open. I'm at the point now where she's getting nearly whole chickens (I'll cut Bruzer's dinner off of a whole chicken, she gets the rest) and 3-4lbs of pork shoulder with the bone as her main meals, or feeding her the largest leg quarters in the package while they are still mostly frozen, otherwise, she'll bolt them down too. She'll take a frozen fish fillet and turn it longways like a popsicle, and swallow it whole. The only thing that takes her a while is the pork shoulders, those she'll work on for a half hour or so.
Bruzer gets his food cut up ever since his choking incident, and he will clear his bowl in about 30 seconds.
Gunnar on the other hand, takes 10 minutes to eat a cheerio. He'll lick and nibble at his dinner, taking his time, not worrying about the others moving in and stealing his food since he rules the roost and they all avoid him when he's eating. He'll take 15-20 minutes to eat 2 1/2 lbs of food, where Daisy can polish off a 4lb chicken in about 10 minutes tops.
Red, I wouldn't worry much about Caiza eating fast. Dogs by nature are gulpers, think about what wild dogs do, bolting large pieces as fast as they can to get more than their competition.