Well, realistically, any part of the transportation experience can be a roll of the dice. I've waited nearly two hours for luggage to come off of the carousel, I've arrived at a rental car counter only to find that they didn't have a vehicle that matched my reservation or that would work, I've had a car service go MIA and I've had lunatic cab drivers going 30 mph+ over speed bumps in a parking lot. I've also had great experiences with DME.
Have guests have less than great experiences with DME? Of course, but there are no guarantees and all kinds of things can happen.
Have guests have less than great experiences with DME? Of course, but there are no guarantees and all kinds of things can happen.