I read an article a while back, I probably linked to it in a post on this board where Bryan Murray claimed Dorion was the one who insisted he trade up for Erik Karlsson.
On the greater topic, I don't think Dorion is that bad. I do not think he is that good. In fact, I know he wasn't serious, but Dorion hit the nail on the head when he said that he thinks he is an 'okay GM'. That's exactly how I'd describe him.
It's hard to fully assess him since we only really have 1.5 seasons of him as GM under his belt, and we haven't seen how Dorion operates in all situations. We've only seen hyper aggressive win now Dorion where he fixates on specific pieces, and doesn't worry about what he has to pay to get them as long as it is relatively reasonable.
I think people have this false idea that if we fire Dorion, things are guaranteed to improve. We're not likely to attract top level GM talent at this point because one, I doubt Melnyk wants to spend that much just like with coaching (walk on water, etc), two, an in demand GM candidate may not want to take a job in Ottawa where there are constraints making success that much harder via the organizational budget.
The only move Dorion has made so far in terms of trades that I would classify as really bad would be acquiring a 35 year old Burrows and extending him, but even that one he was vindicated by the fact that Burrows helped us push into the playoffs, and without him, we might have missed out.
The Duchene move was bad if Turris was going to extend for 6x6, but we don't know if that's true as of now. If Turris wasn't going to re-sign, given where our team was at when we made the trade, and where we should be right now, I don't think it was a bad move at the time.