The more things change, the more they stay the same. I have travelled to dozens of conventions in seven different countries; indeed, the cosplayers and locations are vastly different, but things are more or less the same. From a photographer’s point of view, you arrive around noon, roam to find people you know, then maybe start taking photos or just socialize. By evening, attendees wrap up and return to their respective accommodation, sometimes accompanied by a dinner group. This is not the case for US conventions.
The best way to describe US conventions, in this case Anime Expo, is a giant four-full-days of extravaganza that will entice all senses of the anime fandom, including cosplay. This is the one convention that will never bore you. As long as you retain an exploratory mind (and are awake), there will always be things to do around the clock.
Photos by Shiroin.