I've read four books in this series so far and they are quite different even though many characters appear regularly throughout the books.
The first two were fairly angst free with a touch of paranormal, Suit Yourself was pure fluff - I adored Leslie.
Feat of Clay was a surprise after the first three; it was so much darker and at times almost difficult to read when we got descriptions of and insight into the things Tate had gone through in the course of his last case as an undercover cop.
But even so, this book is my favorite of the series so far. Now, as I mentioned already, I have no problems with bouncy, colorful twinks - Leslie is amazing - but I do like myself a pair of not quite that young, big, strong alpha guys going all soft and vulnerable with each other. And I got that in spades with Tate and Clay.
They had known each other for many years and where already together as lovers at the start of the book, so the drama of the story didn't come from within the relationship. Another plus in my book as that can get rather exhausting at times.
I am looking forward to the next ones in the series - although I do wish they didn't have quite so many editorial/textual issues. It's not typos, but there are quite a few cases of missing prepositions or words swapped around in a sentence.