Smooth Talking Stranger is also my favorite of them with Blue-Eyed Devil at a close second. And I did read Brown-Eyed Girl and enjoyed it, though it didn’t supplant STS for me. Did it have issues? Yes. But, as a writer, I can’t imagine the pressure she was under to write a follow up to such a fan favorite. Basically you’re just trying to write as well as you did before but even better, and without disappointing your existing fanbase. Which is no mean feat.
I felt like the critical response was inevitable because people loved the other books so much. (It actually reminded me a bit of my own response to Loretta Chase’s The Last Hellion, her first book after Lord of Scoundrels, which at the time I remember being wildly disappointed in. But later when I read it without the example of Lord of Scoundrels hanging over me, I loved it.)
Also, did anyone notice how these books sort of anticipated the New Adult first person, billionaire trend? NA owes a lot to Fifty Shades, of course, but at the time these first came out First Person was almost unheard of in contemporary romance.