Letting something go is great but at the end of the day, she left him at the altar. I get that seeing her with Tony and her daughter, happy, made him no longer angry, I just think that was too perfect and would never happen in real life.
The show follows up a major low note with a major high note. I enjoyed the theme of how you deal with uncomfortable people from your past. Going around the table (or rather, the underside of the table) with everyone explaining the figure in the past they were haunted by helped our understanding of the characters (Robin especially), and Ted's avoidance scheme is one of those cracks in the foundation that helps convey his panic and difficulty after what happened to him.
But what puts the episode over the top is the ending. Marshall as Ted's anger coach pulling out the stops with Star Wars, and the breaking point being that she moved into Manhattan after she told him she'd have to move to New Jersey were both great, funny bits. But the fakeout with Ted's rant to Stella was emotional and sharp, and the real event where he sees a happy family and doesn't feel angry anymore is a little too clean, but it's a nice idea. The entire episode is a solid exploration about how to deal with anger, and the middle ground between Ted's initial Ohio-style avoidance and Lily's New Yorker-style externally-directed rage. Barney's a little creepier than usual (even for him), but otherwise there are a lot of laughs here and a blockbuster emotional note to go out on as well.