Yeah, I was flying across the continent about a month ago and had read about the rudders on the Airbus planes and was very worried about my flight the next day. However, just realize that there are A LOT of Airbus planes that fly on a daily basis all around the world in some of the worst conditions for flying and have no problems with the rudder. I don't want to downplay your fear, but I was just letting you know that I was in your position and that it's not as big an issue as some make it out to be. After all, any sane airline would not purchase a plane that was going to have such severe problems with the structural integrity.
The good news is that Spirit's A319s are all relatively new. I was very pleasantly surprised on my first flight on a new Airbus model, as we flew directly through an area of severe storms but felt only light turbulence. The aircraft was also ridiculously quiet.
One thing I will warn you about, though, is that the aircraft makes strange noises during takeoff, which would be disconcerting not knowing that they are, in fact, perfectly normal noises. Just like how different models of cars sound different when accelerating, Airbuses make different noises than aircraft made by other manufacturers.