Definitely a different movie. Everyone I spoke to came up with a 101 "summer movies" they'd have gone with before The Shining- Jaws, Back To The Future, Star Wars, Labyrinth, Yellow Submarine were all suggested.
A more central location, or shuttle coaches running to/from Dublin city centre.
More Irish craft brewers.
More varied food vendors. Vegetarian options. Food stalls to be spaced around the event rather than concentrated in one area. Snack options (Keoghs crisps for instance).
Smoking area.
Get rid of the dwarf.