I liked that Vader line:
"Your strength has returned...but the WEAKNESS remains!"
Something that I didn't pick up on until thinking about this show one day later:
This show was kind of all about Obi Wan going from totally depowered, to regaining his full strength in order to contact Qui Gon's Force Ghost.
We know that Yoda already told Obi Wan that Qui Gon's ghost was waiting to train Obi Wan to make him even more powerful, but at the start of the season Obi Wan's powers have totally faded away, so he has no hope of actually reaching the Force spirit world.
And basically, it was Leia that caused him to get his powers back. Somewhere in there is a metaphor about an old man feeling useful again once he becomes a grandpa.
His Son, Luke.
Here's something I thought of when The Emperor appeared...
Did Palatine actually know about Luke AND Leia the whole time? Is he blocking Vader from sending them just to mess with his mind?