As a reference for the power level of the league tourneys, last night's decks were
>Monarchs
>Maliss
>Magnifistorming
>Branded
>Melodious Exodia
>Speedroid
>Merlantean
>not sure what nyx was on but I know he played Fiendsmith engine
And then goblin and I did round 2 immediately yesterday and I played Generaider vs his KEWL Tunes.
So, essentially, nothing too crazy and about what you've come to expect from /dng/ tourneys. But you should probably have several different decks ready as there's no sending and locking in lists so it would be extremely easy to get counterdecked if it becomes clear you only run 1-2 decks. Also a fun opportunity to learn new decks if you're like me and you don't play too many things.