I played about 10 games on my alt account, didn't want to risk it on the main. What a good decision that was, Ashe was pretty much the deciding factor in every game...it came down to who had the better Ashe, and yes if one team had an Ashe and the other didn't it was an automatic win for the team without Ashe.
I think I might have 1 very good Ashe total on either team. Most were just awful.
Bob is an interesting ultimate that goes from being awesome to totally useless, most of the time being pretty useless. He got slept by Ana, frozen or walled off by Mei, or most of the time, just ended up shooting at a Rein's or Orissa's shield while people killed it.
He did some good work a few times though when no shield or cc was there to prevent the damage he does.
But yeah I would avoid competitive for a few weeks till Ashe stopped being an autolock, and/or people start being good with her.