Well, DH and I just got back last night and I have to say it isn't that bad. I suffer from pretty moderate to severe asthma, and didn't have any significant, additional trouble if I was just doing regular park and resort days, going in and out of buildings. I always have a somewhat difficult time there, but nothing worse than previous trips.
There were two or three days (Tuesday-Thursday of this week) that were worse than others, but mostly it was hardly noticeable. The smell was worse than the air quality, IMO. Many people there at the same time (other guests) discussed not even noticing, although I do find that a bit of a stretch. Hope that helps!