I have many other competitors but from what my members tell me, the two things that make them love WDF (yes, some of the members are really addicted from the start, it's scary) is the style set and that they get their questions answered better there than anywhere else (or at all). I've had a member donate to WDF saying that he would have lost his job if it hadn't been for the help he got there (not all from me).
I never directly attack other boards either, I try to keep a professional community