At first I was concerned about D.VA. Not being able to eat soldier, reaper, pharah ults and not being able to do the primary duty of protecting WInston / supports seemed rough. And then staying in the mech was difficult at first because DM goes so quickly.
HOWEVER, now I've changed my play style to be far more aggressive and really, really digging it. You have to be a little careful diving in solo because you are vulnerable, but you can simply erase so many characters by boosting firing rockets, and using your normal attack and then finally bumping/melee'ing to finish them off. Anna, Zen, Soldier, Hanzo, Widow, Mercy are ~almost guaranteed kills if I can get a clean shot at them.
It is a crazy change in that it is such a completely different purpose for her. I'll be interested to see how it changes the pro game as she really does enable WInston to dive deep. The game has changed pretty drastically the past couple of weeks.