I stopped reading halfway through Soul of the Fire. I felt like he had exhausted his ideas because quite frankly it was getting comical how often their marriage was postponed. Do any of the other books return to the same quality of the first four or so books? Apart from Pillars of Creation apparently.
The last three books are pretty good and kind of have a different twist than the others. My favorite in the series is definitely Faith of the Fallen (book 6) and if you haven't forgotten everything about the series then you may want to push through to book 6. Pillars of Creation is basically an entire book that isn't at all about Richard and Kahlan. You could skip reading that book and I could tell in one sentence the only thing you need to know about it and you wouldn't be lost for the rest of the series.