As a resident of Denver, I go every year. I believe that it is a must-do at least once in a lifetime for anyone who likes craft beer....I just wish I could convince those that like getting drunk (on anything they can get their hands on) more than "tasting" craft beer to skip the event. That would reduce attendance significantly.
As stated, there are a gazillion other beer events, bars, (It is also Denver Beer Week, I think) and brewery tours that are worthwhile, not to mention National Parks, Mountains, and other recreational opportunities abound.