It's definitely not how I would have handled a possible-finale. I don't think the evil timeline shouldn't be confirmed as being real or not, so when the evil characters showed up it was too out there for my tastes. Then it was revealed to be a dream, for which I was both thankful and disappointed by, because dream episodes are lame. If this was the end then it would have been a poor way to go.
But it looks like it's not going to be the end, insiders are saying that the show is about to be picked up for a a fifth season of 13 episodes