I agree with quite a few things you said except these.
Her ult is no where near as strong as Mass rez.
She’s not necessarily hard to play, you just have to master her entire kit to get better value. Her base mechanics are the same from bronze to top 500, it’s her GA and rez that separate bad Mercys from good ones.
This could be said about any hero though.
I love pairing Mercy with Moira. It frees me to focus on a flanky dps or even a Pharah rather than micromanaging the whole team at once (which Moira can do more efficiently). Plus, Moira’s damage orbs already do an obnoxious amount of trickle damage, enough to often steal POTG from ulting dps. Throw a damage boost on Moira as she lets it’ rip and you get ult charge for every poor sucker who gets tickled by that orb, and there’s no way for the enemy to tell that it’s been damage-boosted so sometimes you get kills that the enemy expected to live through.
Back to Mercy by herself:
-Rez and pistol are perfect the way they are
-I’d still like to see Valk get made much more powerful, much more interactive, and last half as long.
-I still wouldn’t be opposed to bumping her base healing up to 55hps. I think giving her 60 back might be excessive, but I think dropping it by 10 while simultaneously buffing every other healer was a little harsh. An over-correction.
Mercy is fine too imo.
Played a comp last night, first round was 8m and i had 14k healing. Yes our tank was feeding, but her healing output is still great, which was my point.
Yes, it is. Mass rez was super niche and often just resulted in people rezzing their teammates to feed more ult charge to the enemy and stagger. It was horrible. Why do you think Mercy had a 5% pickrate in pro play, even with 60 HPS and mass rez? Because it SUCKED a lot of the time, especially against organized teamplay. Smart teams can just reset and save their ult economy without feeding or wasting time. It was also Mercy’s only “burst impact” and sucked up all the remaining power budget from her kit, leaving her weak in other areas and having no E ability.
Current Mercy is like the most picked healer in OWL stage 2, even with 50 HPS and Valk, because Valk is just so much better overall. Longer, more versatile, amazing healing output over the duration (4500 healing over 15 seconds, whereas normally Mercy can only output 750 healing over 15 seconds. That’s CRAZY.). Makes Mercy immune to dives and almost impossible to kill which is also crazy, as that is one of her biggest weaknesses and it eliminates them for 15 seconds. Mass rez only did that for 1 seconds. It also has chain damage boost which is insanely powerful for pushes, securing kills, melting dive tanks who jump your team, and bolstering your team’s ult economy. A team with Mercy on it will be getting ults faster and more frequently because of damage boost, especially if she is Valking every fight or every other fight.
Mass rez just brought 1-5 people back to life. Which she couldn’t even do if she was dead, prompting Mercy players to go hide out of LoS so they wouldn’t die with their ult. Now she can keep them alive in the first place, and well as keep HERSELF alive, and she can even rez someone if they die in spite of her increased healing output. Way better, way more proactive, and way stronger.
I’m inclined to agree.
I believe that whether it’s through a revert, a rework, or simply through some minor buffs/tweaks, Mercy can definately use some improvements to her current state. Based on what they’ve said, here’s hoping that we get to see such improvements from the devs in the near future. 
~Sincerely Yours xoxo,
a Lover of True, Fair, and Fun Balance.
xavvypls 
Yes that sounds good on paper, but that is assuming you are holding m1 and your beam is connected to all 5 teammates through the whole duration. (In which case you’re not damage boosting, pulling out your pistol, or rezzing.)
Zenyatta can heal 9000 in 6 seconds, on paper. (300 hps for 6 seconds on 5 teammates.) The reality is, Zen ult doesn’t heal 9000 health when ulting. Everyone has weaknesses to their ult, but I firmly believe that mass rez is stronger than Valk. Good teamwork can work both ways it isn’t always one sided.
Statistically, she’s in a much better state than she was before patch 1.34. She’s almost meta.
What more do you want.
Take away her infinite pistol ammo on ult (she doesnt need it) then either do 1 of 2 things:
Combine her healing and damage beams into 1 during the ult (nerf numbers if it’s too strong)
Or, keep the healing the same, but add a damage debuff to her primary target in the chain (target takes 10 less damage)
The first one you would use offensively for a push. The second is to save your team more like zenyatta.
It isn’t just good on paper, it’s good in practice. And even if your team isn’t all clumped up, you have HUGE beam range to heal everyone, no matter where they are on the map 
IKR, it has a lot of healing potential! But idk why you’re comparing trans to Valk…they serve two entirely different purposes and each are stronger in different situations…Mercy’s ult isn’t supposed to be as purely defensive as trans.
You can believe whatever you want lol…doesn’t make it true. Statiscally speaking, she is stronger with Valk than with mass rez.
But regardless, Mass Rez is never coming back (thank god 
) so this discussion is irrelevant
My point is, any ult can sound good when you reveal numbers but like you said it depends on the situation, so using numbers to say why Valk is better means absolutely nothing if your team can’t capitalize on it.
Trust me I don’t want mass rez back either. 
Remove rez and let her heal for 60hp/s and let her shoot while healing at same time and I’d never ask for another Mercy change for the rest of time
That would be in complete opposition to mercy’s entire character concept. You’d be turning the pacifist who can bring people back to life into just another dps-support.
It’s just my opinion, doesn’t mean it’s right or wrong, that’s just how I’d personally wish her kit to become, as a Mercy player myself. I am no longer attached to the self-cc quicksand rez and the passive in combat can’t fight back without giving up your healing capabilities
Sorry, I respect your right to your opinion. I just mean that it seems like such a departure from her initial design, I don’t think it’s likely. They can’t get rid of Rez entirely, because Mercy mains will riot.
That’s like the biggest nerf she could receive D: and completely against her design philosophy.
Personally i dont like how mercy is atm… i feel like she needs a bit more skill ceeling to her Character…the rework kind of dumbed it down a bit too much