I used it last year. I also carried all the other guidebooks (Yogi's guidebook, the Wilderness Press data book and guidebooks). I found I mostly use the PCT Atas because it was convient to just quickly glance at it and know where to go. And yes, it does seem overpriced, but I broke down and bought it in Big Bear after being on the trail for 3 weeks. The WP guidebook maps are enough to hike the trail (and for many, that is all they use), but I like having better maps. An alternative would be to print out Halfmile's free topo maps at http://www.pctmap.net/. But printing that many color pages would be expensive in terms of buying color toner.
The Atlas was done using a GPS track so the mileage differs from all the other guidebooks. I personaly think the other guidebooks mileage is more accurate (or at least more consistant with itself) as there were times the Atlas mileages seemed longer then other times. You get the normal compaints on the elevation profile missing climbs all the time. It also doesn't show some of the most common alternate routes such as the Eagle Creek Trail in North Oregon that most PCT hikers take. But overall, it is a good product, I just wish it was cheaper.