Tough Customer is one of Sandra Brown's recent novels. It's a suspense novel (although this time I clearly saw the ending coming) with a hefty dose of romance thrown in.
While I was slightly disappointed in the plot, Brown did something really interesting with the romance subplot. Brown took the standard romance sequence of events and split them over two couples. It was interesting seeing different aspects of the love story play out in two different story lines. I was also fascinated by her ability to get two characters to believably fall in love while never being alone together. Constantly in the presence of, and watched by, others, their story is still believable.
The flaw for me in this novel is the bad guy. His character seemed very flat. Instead of showing us his motivations, Brown told us about them. He then commits what should be a deeply personal crime through a puppet. It just didn't ring true for me.