Seems like a little more effort was put into zOMG for the event than the site. In years past, I always look forward to the site event stuff, but now it's all zOMG and less site.
I love the ghost fighting idea and it was really fun to do, but short. I'm glad all the bosses were not unlocked at once and you have to wait a day or two before the next one shows up. That was a good idea, so you don't get the whole site event done in one day.