As a Reinhardt main, I will say Ana is the best thing to happen to me since I started maining Reinhardt (not by choice, see below). I don't think any other character becomes as lethal as Reinhardt with the Nano-Boost. Roadhog comes close, but only if his Ult is ready.
Anyone else have to deal with the frustration of being naturally gifted with a character that, while you don't mind it, you'd rather not play? All my life I've never played Tank. I've only ever picked things off from afar or got nice and close with a blade. I live by the infinitely wise words my boxing coach gave me back in the day: "Don't get hit." And yet I find myself better able to assist my team to victory as Reinhardt than, say, Tracer or Reaper (though admittedly I've only got 3 more hours on Rein than Reaper right now). It's to the point that when I play with my regular guys I say "I wonder what I'll be this round..." and everyone laughs thinking I'm making a joke about how I only ever play Reinhardt now, even though sometimes I'm actually trying to play someone else.
But then I get called things like "Best tank ever" and "a god" and I wonder if my preferred playstyle all my life is not the playstyle I'm best with.
Now that I think about it, in Soul Caliber 2 I was always Nightmare playing against people. That was because I learned his moveset and utilized it in such a way to maximize mobility (my god some of those stance-change combos...). It's kind of similar with Reinhardt, I don't play him vanilla. Unless I'm needed to shield a path (getting the team to rush into the left side of the first arch in Anubis for example), leading a charge (literally any B point), or standing on a payload, I'm using Reinhardt to sneak around my enemies and draw attention from my team doing what they're doing (usually sucking, unless I'm in a group). I'm dead for more victory screens than not, usually because a sneaky Reinhardt is a mean motherfucker. The Supports should know to fear me.