I realize that the Chronicles are stat light and fluff heavy, but I was very disappointed in this product for the simple reason that a book titled 'Princes of Darkness' didn't have stats for the archdevils.
This seems to be a trend in PF so far, with no high level content released or even scheduled for release from Paizo. While the Beastiery had stats for some high level monsters (pit fiend, Tarrasque) overall high level stats are few and far between so far from Paizo.
I can only hope Paizo rectifies this once they finally create epic rules for the Pathfinder system, as the archdevils would certainly qualify.
On the plus side, the narrative concerning the devils is well written and informative. I'd have given this product 4.5 or 5 stars had there been some attempt to stat the archdevils, even without solid PF epic rules in place.