That is a tough one. That day is crowded, so more touring time would be nice. We did the early Luau in February, it was great. I have read on these boards that for the 8:00 Luau it is very late before you can make it back to your rooms. If this would be a problem for you I would leave it as is. If not I might try booking the later one to allow more time for Epcot.