Thanks for the PM. I saw your message and went to see his stream. Yeh, he is very mobile character and I can understand why some people will want it nerf. Keep in mind that this is still in testing and Blizzard might adjust some of his abilities before it officially gets into the game. I personally think his ultimate ability, the Meteor Strike is kind of boring, Blizzard could have came with something more interesting and with different outcome than just stun and damage.
I think that Doomfist will defensively get into the meta. Just seeing Seagul playing it you can see how devastating this character can be in the hands of a professional Overwatch player. Mobility is the reason why Genji is so powerful character when played by a skilled player and Doomfist is much more mobile character than Genji, he an jump up, storm forward, stun, shoot, evade depth with his ult and all that in a very fast pace gameplay. He can ever storm like 20 meters with one movement, and can reach high places like Winston. The only thing that still make Winston a good character is because he has shield.
I'm sure that if you visit reddit you can see plenty of player ranting about this character, but to be honest, it's really enjoyable to see him in play.