Despite the year-long buildup, it still felt a little sudden and pat for how the Ascendant Arc ended. But otherwise, I think it was handled exceptionally well. This really felt like a season finale and and I can't wait to see how everything will be set up for the next season.
Kira's decision (and I'm glad it was hers, rather than forced on her) was completely in character and felt completely inevitable given the events of the last few episodes.
I must admit on being surprised about Vaughn being sucked into the wormhole. It was a wonderful arc showing him forgiving and coming to terms with Ben Sisko. Just surprising since I was ready for the finale to show Captain Vaughn take over the station. But there are good things in being surprised.
And finally...finally..Dax is leaving, and so is Tarses. I like his character, but after last episode he was thrust into an uncomfortable place and it totally made sense to advance his career that he would transfer.
Once again, good job. I'll be interested to see what happens when Vaughn inevetiably returns and (I would assume) commands the station for a short time. That can cause some friction.