It should be double elim, but I'm actually going to be seeing the tournament director this weekend and will ask him to confirm. As far as the level goes, in E you'll see a wide range and it largely depends on the state directors that the teams came from. Viera is the nicest complex I've ever been at, I think it's something that every player should do at least once is go to Worlds. If you don't take it too seriously, even if you go 0-2, you can still have a weekend in FL and many of the major players get together to play in the Mixed Major event in the Stadium. I've been asked to work it many times but I only get one weekend to go down for Worlds, this year I'll be down for C and Women's.