I loved the first 4, and waited for the 5th to come out for ages! (like 12 years or something) and then it was such a dissapiontment! Ayla seemed a completely different person, and I thought everything was just a bit "over the top". I just don't believe such a society could exist there, too many people in one place. That doesn't happen anywhere they went before... And in the first 4 books there are a lot of things that make you think Ayla is somehow important...and now she is just a woman, fitting in. maybe a bit special, but not as different as the previous books make you believe.
oh, and I think there's too many sex-scenes...did she write those to sell more books? I have nothing agains a well-written sex-scene that fits into the story..but Auel overdoes things a bit.
But i am going to read the next 2 books (if they ever see the light...) just to see how the story ends. And I do have a bit of hope things will get better in the next 2(?) books. The first four books were wonderfull, so you never know!