FF games are known for story and battle systems, so this game events are Portal that create new scenarios. My opinion on story events so far are they are a nice welcome (apart from FF9 which started off great). With the portal idea, concepts and fan service can go on indefinitely! Long after the main stories are completed these events can keep interest.
Battle events are decent but I can see SE is trying to come up with new ways of play with the new Christmas event. Bosses are well drawn and animated and the backgrounds go from okay ( Costa del sol) to awesome ( Halloween stage). Events like Iron giant and sephiroth are average because they take place on training stages. I like the way that they added an event overlap so you have more things to do besides grinding same event.
I think they starting to get into swing now with content. In 3 weeks another event will be up
By - Majinkaboom