Has anyone tried playing with more than 4 players? I've got a gaming group that just started and we have anywhere from 4-7 players a session. I wanted to introduce them to LCGs but I'm not sure how well this would translate into larger groups. Would it just be way too easy?

It wouldn't hurt to try. I would play like so:

1. No one can play the same hero as any other players (limit one copy of a hero in play).

2. No more than two players running a majority of one sphere (e.g., no more than two entirely Spirit decks).

3. 1.5 cards, rounded up, off of the encounter deck per player, per turn.

4. For every two players after the 4th, add another copy of the encounter deck, still obeying any X number of card Y per player text that may appear on Quest cards and Encounter cards. 

I think you're better off having two separate games going on.

Try this: http://www.fantasyflightgames.com/edge_foros_discusion.asp?efid=201&efcid=4&efidt=565827&efpag=0#566032

6 player variant with evil game master :-)

You could play 2 seperate games on the same scenario and have a competition for score between the groups.