Back in Legion, I enjoy clearing old raid on my Fury Warrior. With Bear Tartare, spammable Whirlwind, Aggramar Stride + Sephuz, blasting through old raid was a breeze.
Hunter and Shaman were also my favored old raid solo class. Trailblazer/Ghost Wolf are great for speeding things up.
Now in BfA, Bear Tartare and Legendary are no more, I feel so much slower in old raids. I clear them so much faster on my 110s who still have access to Legendary than on my 120, and my 110s kill things just as fast as my 120s with the exception of Draenor/Legion raids.
I only know Warrior and Shaman since those two are my only 120. Warrior are slow as fk, Shaman is actually pretty decent due to Ghost Wolf gaining another 20% speed in BfA, but ofc these doesn't make up for the loss of Bear Tartare.
So how fast are other classes at clearing old raids?