Just played Descent Into the Lost Caverns of Tsojcanth on StartPlaying as part of their collaboration with WotC on 50th Anniversary events. I did a "fun run" session rather than a regular tournament. I had my evening free and joined on a whim. I had fun but wish I could have played with the tournament rules just to see how the tournament games are run. I do think, however, that playing a tournament game would be more fun with a group of friends who have been playing together for a while. Playing with strangers makes it hard to play tactically and make decisions quickly. I could see many players in a tournament game getting frustrated with one another, especially if play styles and experience levels differ much.
Also, I played with a pregen. I ended up with a 9th level monk. Highest stat was Wisdom. Only magic item was a rope of climbing. Makes combat more challenging, I suppose, but didn't feel like a character a typical player would ever create.
The 4-5 hour adventure is a typical dungeon crawl, which I think works well for tournament play.
I'd be interested in hearing from others who have ran or played in this using the tournament rules.