I picked this up kind of expecting more Ra's than i eventually got, but i like the ideas in it so much that i don't mind that, really.
Rather than a straightforward retelling of Ra's early origins, we have Batman taking on a case that leads him back to certain key moments in the life of possibly his most brilliant and deadly foe. I actually kind of like that idea; it's more ingenuitive and interesting than just copying and pasting other "year one" formats.
However, though the narrative voice (a letter written by Ra's before he died) does guide us through his philosophy and world-view very well, and is wonderfully and evocatively written, by the end of the book i felt a little short-changed on the Ra's front. We basically get two flashbacks (good ones, important ones) to Ra's past life and then the rest of the story is Bats doing what he does best. Now, that's fine, but not what i was expecting when i picked the book up, and in terms of seeing behind the scenes of Ra's personality, well, that doesn't really happen on a grand scale. We get told he's brilliant, ancient, ruthless and get a few momentary insights of this. That's fine as far as it goes, but i already knew that. I never doubted it. I would rather have found out why it was the case than just have it reiterated again.
I liked it. It's good stuff, and any batman fan will enjoy the story, i think. I did. It just might not be quite the story they were expecting, is all.