Writing for Amy.
We have done at least four of Steve Allen's Canyoneering 2 routes and have these observations to offer. His routes have all been fun, challenging, interesting and have taken us into wonderful country. His directions are well written and very accurate at the time they were put down on paper. In my opinion, the comments about his overrating the routes are a little off target. If you look at the ratings from a strictly technical point of view, yes, he probably does overrate. But placed in the context of a hiker carrying a load often many days from a trailhead and with no possible prompt (any?) assistance if something goes wrong, then no, I think his ratings signal that you better be really careful in this area and don't get in over your head.
Descending Robber' Roost (Dirty Devil North) is a fine trip but requires multiple rappels. If you don't know how to do this safely and with the understanding that the last person to rappel will be unbelayed, the RR is not the place to learn. The class 3-4 ascent of the large cliff face early in the trip is exposed and on steep down sloping slabs. In my opinion, most people will want a belay here and for good reason.
The Dirty Devil South is a fine trip and the traverse over the Block is as good as it gets.
We greatly appreciate what Allen has done in writing his books. We didn't have the resources to plan the convoluted and rewarding routes in Utah that Allen put together based on his years of experience in the backcountry. If you have only done one trip in the area, there is so much more to see (we have done at least a dozen backpacking trips there) and Allen offers a way to do this by sharing his deep knowledge of the canyon country.
-James