Well, personally I'm at 30% of the third and I enjoy it. In my opinion, for what I already read, the second one is a bit behind the first and last (at least the beginning) where I really find back what I loved in the first (basically the author take time to give the context about characters in full details).

Now, if you don't enjoy, well everyone his own tastes, don't feel ashamed to not finish the series (or even a book), there are so many other books you may love, why wasting time just "to finish"...