Handling seems more consistent to me. I have improved since moving from F104x1 to V2.
Durability, the worst you can do on the original F104 pro was maybe tweak or break a T-plate. On the V2, the plastic side links bend or break easier, I've gone to Associated balls and links, and seems to be holding up slightly better. I've also managed to break the plastic center pivot, but it was a really, really bad crash. Overall I think the V2 is fairly tough.