Forgoing Spoiler tag because, well, at this point in the day people will have seen it if they wanted to.
I agree with Sean, above, for the most part. A big thing I noticed was that, while ObiWan was really rusty...Vader wasn't doing much better. He lacked a proper lightsaber form, using only a single handed grip and his raw strength rather than any real technique. It's hard to tell if it's a "rage thing" or just "body adjustments". It was a sloppy fight, and it felt natural in this scenario: ObiWan hasn't used a lightsaber in years, like never practiced to keep his basic skills up. Darth Vader has likely never had need to practice his own skills since, at least in the visual media cannon, he's never faced an opponent requiring much from him to deal with. Doubly so since the Inquisitors are around to do a lot of that dirty work.
So, I suspect we will end with ObiWan reconnecting to the force, putting a good trouncing on Vader, and step into becoming a true "master" and able to hide his presence without disconnecting from the force. Remember, Palpatine was able to hide his own presence next to HUNDREDS of Jedi.
Still mad props to the actress for Leia. She is just NAILING it.
