I have just received the Fairfax County card which actually took longer then the FLP. I am sad to see that Fairfax has way fewer suspense books, and most if not all are available at FLP.
For someone trying to decide which library to join, I would advise joining one and seeing how many of your genre are available. At renewal time, I will not renew both cards (unless of course, there are huge changes in the next year.) (**fingers crossed**)