Great episode, it's the first I'm gonna rewatch. Wasn't perfect and felt fan-service-y, but very satisfying still. It carries a lot more weight if you've watched The Clone Wars. I feel Episode 4 is a better episode, maybe even 3, but this one carried much more gravitas to me.
Anakin teaches Ahsoka to let go, helps her through what has to be some pretty heavy duty PTSD not to mention guilt from the Clone War and letting him down. I think it's fuckin' awesome that they took the time to address it at all, her and many other Jedi were child soldiers after all and Ahsoka didn't just take out droids, she probably killed at least dozens of people too, probably hundreds. Her entire adolescence was bloodshed and to top it off the Order that sent her to do those things stabbed her in the back, her master went on a killing spree, and it turned out everything she was fighting for was a lie and completely pointless. That is an immense burden to carry, it's a wonder she didn't have a psychotic break long ago.
What I wonder is if the battles were lacking visually to keep the budget down or are supposed to be a literal visual representation of "the fog of war." Perhaps both. While the show isn't perfect it's definitely not lacking for heart. Her character changed after too, like her personality came back. While I think that kind of trauma should've been explored for a longer time period I'm glad it was addressed and I suppose dying could be enough to shake the fog off.
As far as how she stayed alive for so long underwater, who knows. I wish that was addressed better - even though she's a force user I think "mystery" did a little too much heavy lifting here but I'm okay with it I guess as Jacen said he heard her fighting so it does seem like she physically went to a different place and then was returned to the water.