I agree. While some of the characters were underpowered since fighting all of those Foot ninjas shouldn't have been such a problem for the Ninja Tribunal, it did feel like a solid conclusion to the series. I would hope that that was the last time the Turtles would face the Shredder since after defeating Utrom Shredder a few times, having him banished, and killing the Demon Shredder, Cyber Shredder didn't feel like that much of a threat. Or it might have been that I was tired of seeing the Shredder reappear after they thought that they defeated them again.
I don't think that it was a perfect ending, and those kinds of endings are hard to find anyway, but it felt satisfying enough for me. It was definitely better than a cliffhanger ending that a lot of animated series have had before.
I actually think that this episode is top ten material. Not only for seeing all of the cameos coming in left and right, but it did bring a nice sense of conclusion. Plus, I thought that ending with April and Casey getting married was really sweet. This was definitely one of the best episodes in BttS, but I think that I would have placed it at number seven and then place "Same As it Never Was" at number five. Even so, it's still a nice episode to put on this countdown.