Looks like the R8 is been balanced shortly after the release, sadly, we have a new op toy into town.
Look, I played TF2 for years and I'll say, the Plohg now is a must have. I don't know if they changed the code of the flamethrower but it melts everything super fast with kritz on. Many Pyros just run to you, activate the "ooomph" in the front of 3 or 4 people and still managed to kill a couple before going down.
Yeah, shoot him down before he reach you... I USED to do that as a heavy and it worked but lately he just kill me before I kill him, and I put some distance.
Even if the whole team focus him at the same time, it's basically a 3 second "taunt" where snipers / spies / scouts are free to do whatever they want because people NEED to take the Pyro down.
I won't say "nerf it" thou, I'll just do what I do every time a imba weapon is created, I'll use it and savour the delicious salty tears.