Actually, the Feehan books are my secret vice...

The second book in the series, Dark Desire was my favorite. These are a lot like the old gothics of the late seventies. The heros are the kind of guys that if you met them in real life, you'd (hopefully) run as far away from them as you could... controling, manipulative (for your own good!)... but controled by the author, they are fun. These books are candy, but only if you like this flavor. They are way over the top and make no apologies for it -- which is why I enjoy them.

Dark Guardian was actually my least favorite of the series -- because I couldn't stand the heroine (her situation was just a bit too unbelievable for me). I had a heroine problem with Dark Gold as well. Dark Desire (with a real tortured hero) and Dark Fire are pretty good.
I have the feeling that a good editor would help a great deal. (As a writer with a terrific editor, I'll tell you editing is a Very Important part of getting good results) For instance, Dark Fire is set in France -- but none of the characters (not the doctor with the hots for the heroine, nor the little girl rescued or her abusive father) have French names.). Similiarly, with the exception of the cemetary, the setting doesn't feel French. She needed to watch a few of the Highlander episodes set in Paris

From what a friend of mine who writes for Leisure says, the authors are pretty much on their own.