Keith:

I have been searching for several years now in hopes of finding the perfect 3 wood...I have probably tried everything out there. Finally, I found the perfect club for me...can easily get the ball up in the air from the deck and can still hit it from the tee. I have finally bagged the 913Fd with a Graphite Design Tour DJ 7s shaft. I feel that the fd head is better for me; i had difficulty hitting the 913f off the deck consistently. I am not sure where you live, but if you are in the Los Angeles area; go to PLAZA GOLF (WLA or TORRANCE) they will let you check out their demos (they have both F and Fd) and take them to the range or play a round of two with them, your answer will come to you. Good luck. Hope this helps.

Alright I have both of these clubs and the main difference between these two is that the fd is meant for a lower trajectory with less spin. Its kind of meant to be a driving wood so if you dont wanna hit driver but you want a wood that you can easily hit off the tee where as the normal f is a wood designed to be used off the turf to get a higher trajectory and a little more spin.

It really depends upon how you are using the club.  I generally use the 3-wood as a replacement for the driver when the driver is too long for a particular hole or it is an extremely tight fairway and accuracy is more important than distance.  Because of the way I primarily use this club, I carry a 913fd because it has lower spin and a deeper face.  I do occasionally hit this club off the deck and it works fine, but just tends to launch the ball lower than a 913f which was a better setup for me for shots in the fairway.  Think about how you most commonly use the club (tee or deck) and that, along with trying both variants and being properly fit, will push you in one direction or the other.