My impressions so far:
That which was wrong has been fixed; it's no longer painful for writers, editors and proofreaders to open the book. Errors remain, but there's practically no such thing in publishing as an error-free book. But no more Spellb.ooks!
SRD Cut-and-pastes are gone, replaced with clearly worded examples that consider the game at hand. In addition, there's less reliance on knowledge of/access to the SRD; this is much more of a complete rulesbook.
The layout is not so very different to the casual observer – that's me for now, because I'm not about to go page vs. page with the first edition.
There's some very nice new artwork, and some older pieces have been moved around.
Many of the expository quotes from Conan stories have been axed in favor of more artwork, charts and graphical examples. Enough remain to remind us of the source material and Mongoose's excellent faith thereunto.
The only Direct Rules Contradiction (TM) I've seen so far involves everybody's favorite argument point, the 5-foot step. The rule specifically states you will provoke an attack of opportunity if your 5-foot step is combined with an action that provokes an AoO. Firing a missile weapon is such an action. Yet on the same page there is a graphic of "Valeria" 5-foot stepping away from a "Pict" and shooting him with her bow, without drawing an AoO. :x
All in all, I'm very pleased with what I have now. I was pleased with the original, but the Atlantean Edition is what the first edition should have been. Many thanks to all concerned.