I loved this episode. It really helped to flesh out Toph's wild side, and added some much needed humor-focused storyline. I couldn't wait to see what happened next in this episode, as it just got better and better. This also is the episode that contains the new 'best' picture of Sokka to date (hence my icon). But the thing I love this episode for the most is finally allowing Toph's character to voice what so many of us were thinking about Katara. Way too motherly and bossy. I found it inappropriate during "The Chase" how she was ordering Toph around like she knew what she was supposed to act like, and was glad Toph was able to payback some words.
The mudfight at the beginning of the episode wasn't too bad either, and brought an interesting thing to my attention. Much like the sludge from a previous episode "The Drill", the mud is a 'bendable' for both Earthbenders and Waterbenders. I will look out for more "Multi-element-bendables" when re-watching episodes from now on.
The part that did throw me off was the part about Toph getting thrown in a wooden cell instead of a metal one. As some posts have suggested, there is no on-screen evidence that Combustion Man had any knowledge of her ability to bend metal, nor any reason as to why the prison had wooden cells at all. I think it was a poorly implemented set-up into the next Episode "The Puppetmaster" for Katara to learn more waterbending techniques.
All in all it was a great episode. I couldn't stop laughing more almost all of it.

I felt this episode was too quick of an advancement in the way of waterbending, especially for Katara. By the end of the episode, Katara has learned to bloodbend, but this doesn't have any consistency with the amount of time and effort she had to put into her former moves. She took months just to learn to push and pull water. She took a few days to even perform a simple water whip from the scroll. Even after training at the North Pole under a master. Then, when Katara attempts to fight Hama, she isn't even taught anything about the bloodbending technique. It is simply used by Hama on her and a few moments later, she is able to do it back. This move took -years- for Hama to create and master in prison, yet somehow Katara is just able to perform it with nothing more than a glance.
Although the move itself and the other waterbender survival techniques were interesting additions to waterbending, I felt they presented and wrapped it up far too quickly as an "Oh by the way" episode, to simply establish a premise for Katara to use the move again later in the series when she must.

This was a great episode, but it didn't end up being the pivotal point that the story had made it out to be. It looked to me like we built up to this episode over half of Season 2 only to get to a two-part failure on the Gaang's part. I did enjoy seeing Aang with some hair though, and I'm sad to see it go. At least the invasion animation was done very well. The fight onto the mainland was fun to watch, and seeing the Water Tribe's battle armor was a reward in itself. However, I do feel a little cheated by the Day of Black Sun episodes as a whole. Part II bested part I in my opinion, and I hope the finale will end up tying everything together in a non-cheesy fashion.