On the A319/A320 flaps 3 increases the pitch attitude vs a flaps full landing, but tail strike is not a large concern on those versions. You do have better crosswind control and go around capability as well as a quieter approach with less airframe buffet. Bean counters say you save maybe 50 lbs of fuel. You pay for that with higher pitch attitude on touchdown, longer float, longer landings, increased tire/brake wear etc. On the other hand, flaps 3 ( a different flap design) on the A321 decreases the pitch attitude vs flaps full (approx .9 degrees) and does give you some additional tail strike protection on an airframe that does have a tail strike concern. We are told in training that the next crew that hits the tail landing flaps full in a 321 when they should have landed flaps 3 will be hung out to dry in the investigation. Of course if you run off the end of the runway you won't get any sympathy either.