Personally I think this might be the bargain deal of UFA for the Leafs.
Yes, he has warts in his game, but with the way the Leafs roster shapes up -- specifically having Matthews who is obviously not only the best goalscorer, but a very solid defensive player; creates several perfect roles for Domi.
It might be as a winger with Auston Matthews; where if he continues as he did towards the end of the season, would have a decent chance to set new career highs. It could also be in a #2/3C. Obviously he doesn't have the defensive game to be your typical #3 shutdown C, but with Matthews taking a ton of best-on-best matchups, if Tavares' eventual replacement is a little more defensive minded, it's likely a great fit.
I personally also like the fit alongside William Nylander.
Plus, you get a guy in what should be the absolute prime of his career, with the security of a multi-year deal. He's obviously bounced around a ton -- he can now begin to develop some long term chemistry.
From a contract standpoint, a guy that has a really good chance to put up 60 points for under $4m is a steal. If it doesn't work out in a year or two, it's an easy contract to move. You look at the deal Bertuzzi got... and to me, I'd probably take Domi over Bertuzzi on equal contracts.