Might not be a popular opinion, but personally...I'm ECSTATIC about this trade.
Sure, Weber is four years older, which is quite important. And Subban is highly skilled. However, he also comes with his fair share of issues on and off the ice. In my opinion, Subban didn't show any improvement last year. While he did get his fair share of points last year, he wasn't the offensive treath from the point, especially on the PP, that he needed to be for a good chunck of the year, and didn't seem to care all that much. Defensively, he slighty improved overall, but that was negated by some very stupid and egoistical plays that made a lot of fans cursed.
Off the ice, he clearly wasn't a fit with Montreal's very conservative ways of doing things. Every reporter in town had reported, at one point or another, that Subban wasn't appreciated in the lockeroom...not only by guys like Plekanec or Pacioretty, but pretty much everyone else. Price is the only one who seemed able to keep him in check.
Obviously, Subban never was Bergevin's guy. Molson forced his hand into giving him that $9.0m deal.
There's a lot of negative in this deal for the Habs, if you want to support that narrative. But there's also quite a lot of positive. Weber's current caphit being $1.0+ less than Subban, his leadership on the blueline, doesn't quite have the offensive potential for a 60+ points season like Subban has, but still has a booming shot from the point, an potential to hit 20-goals easily, much more responsible defensively, a lot bigger than Subban...
To be honest, I really don't mind seing Weber come in, and Subban go out. At this point, I think it's best for everyone involved.