I wouldn't advise looking at the appb values as the sole way of determining difficulty; in fact, I would say that the values on the spreadsheet (which I'll update and post, along with some of a write up, at.... some point in the near-ish future) are more important. The "adjustment" values are rounded some for my ease of use, and only consider the top 200-300 teams by ppb. I think it's far more important to look at things like the median and the first quartile values, since the performance of lower teams is more telling of the difficulty of a set.
All that said? Without having the data in front of me right now, DAFT was definitely one of the three or so hardest actual high school sets this year, and might be the hardest.
University of Kentucky CoP, 20XX
hsqbrank manager, PACE member (former President and At Large member of Board), NAQT writer & subject editor, HSAPQ freelance writer, former hsqb Administrator/Chief Administrator, 2012 NASAT Tournament Director