Ana is now available for everyone on PC to play, and like I said in my original assessment, she's great. After playing her for a bit today on live servers, though, I do have a few issues. Ana is a support sniper. She does the heals and the keels. My biggest issue with her doesn't even really stem directly from her so much as it does the way the game currently functions.
She can't get a Play of the Game to save her life, despite frequently saving everybody else's life. Like other supports, her main skills aren't really conducive to it, but she doesn't even have an ace in the hole like Mercy's mass-resurrection or Lucio's ability to shove half a team off a cliff (and laugh and laugh and laugh) to make up for it. Ana is PotG repellent, even as her ult practically gifts them to offensively geared characters like McCree and Genji.
So that's one thing. I also feel like Ana's shooting could, well, feel better. I understand why she can't get increased damage off headshots (she'd be crazy OP if that was part of her dynamic), but as it stands, shots ring kinda hollow. Better sound effects might help, as evidenced by how dang satisfying her grenade can be even when you toss it near your own feet for a self heal.
The third issue is both the biggest and the least Blizzard's fault. I've seen quite a few people playing Ana in ways that range from Real Dumb to How Are You Playing Overwatch Right Now Because You Are Clearly Three Possums Fighting Over A Ball Of Garbage. Don't pick a support if you're not going to support! Plus, Ana's terrible as a pure offensive character. You can pick up the occasional multi-kill with her grenade, but her weapons are built to do supplementary damage, not turn you into Widowmaker 2.0.
But I almost feel like the other two issues might help weed out the third. If people aren't picking up sweet PoTGs and pulling off mad satisfying kills as Ana, they will be less likely to play her that way. That paves the way for her to become a less common pick -- for folks who really get her to be the main ones who bring her into battle. I've found her to be most effective as a counter-healer, to be played in tandem with a Mercy or Lucio while fucking over the other team's Mercy or Lucio. Harass them with fire if they're not well defended, drop anti-heal grenades when they're about to go for a big heal, sleep them right as your team's going for a big push and so on. Ana's not-so-secret secret is that she's wicked good at making life hell for enemy healers.
She might not get Play of the Game for it, but good teams had better recognise. Plus, Ana wins Mum of the Game every single time, no matter what. Of that, at least, there is no doubt.