I think I just need reassurance because we've booked FQ for June and from some of the reviews on TripAdvisor that I've read, it seems to be a dirty resort. I requested building 4 for close proximity to everything. Should I be worried at all? 

What's the definition of "dirty"? Everyone has a different definition of the word. Some people will be highly offended if they walked into a room and a trashcan was still full but everything else was fine. It just means the housekeeper forgot to empty the trashcan once.
Don't go by anyone's review. If you did, you'd never stay at any Disney resort or eat at any Disney resturant or even ride any Disney attraction. Because someone at some point over the course of the past 36 years will have had a negative experience. And we silly humans are quicker to complain than we are to praise.