The F Model US puts a nice variety of shot shapes into a player's bag with its unique flight tendencies. The US designation for understable is apparent out of the hand thanks to its high speed turn which makes the disc drift right for a right handed backhand shot. What makes the flight unique is its noticable finish at the end. This gives players with lower arm speeds a nice disc to throw longer S shots with and those with more power a nice understable option that can handle some torque.
F Model discs are a great introduction into "drivers". They're made for controlled, accurate shots at a long distance and have a smaller rim for a comfortable grip.