In all honesty, boarding early just doesn't really matter that much. Boarding before the very last group might be important, but chances are if you check in early enough (say 24 - 8 hours before the flight), you'll be in the B to early C group, which often times is more than enough to get a good seat.

Boarding early is not a good thing (see my BS fare thread) imho, I'd rather pick my seatmates than have them pick me.

Whenever I fly WN I always pick B or C. It doesn't matter to me all that much. Even when I board C there are aisle seats available for me to grab.

Cheers.