Back when I was a frequent flier I used to rate conferences based on the following criteria.
More cynically, I would rate the venue based on minimal standards of comfort as well as the availability of food and coffee. I have a peeve against hotels that let the coffee run out and/or that whisk everything away promptly at the end of the scheduled break. To deprive me of coffee because a poorly organized session ran 15 minutes past its end time is to add insult to injury.