I thought it was actually the most well executed recap I've ever seen. Start from their shameless announcement that it was a recap episode at the end of 15. Most other series try to make it sound important by calling it something like, "memories in the rain" or try to sell it off as some important transitional episode with 10% new material. Not here. Kamina: "This is a true summary episode!"

I like the way they presented it. I watched it raw (kind of unnecessary to see it subbed) so I don't know what the text said, but the penciled drawing of the title was really neat to see. Then they presented it exactly how the series progressed. Looking back at some of the title images, you can separate Gurren Lagann into two Acts (so far). There is the Kamina Act, ending with his death, and it has appropriately garish and thug looking text for each title. Then there is the Nia Act, with it's flowery title font. She's now the main support in Simon's life. The music fit really well too with each part.

The midway eyecatch screens were a compliation of all the eyecatches thus far.

Lastly, the storyboards as the ending was a really nice touch. It was very interesting to see how much more mature looking Nia was drawn originally.