IMHO - I'd be happy if Transformers was made by this team. They treated the characters and the franchise with respect, didn't do unnecessary redesigns, didn't add new characters - instead they went deeper into the relationship of the Turtles. The whole concept of the plot is about family, even the chief 'villain''s plot is about this.
Mostly Ralph and Leo get the spotlight, and I must say I really liked their confrontation near the end of the movie. Ralph becoming a vigilante was a great idea... Especially when Casey joins him. Don doesn't do much, Mikey is an idiot as always...

Minor characters are well-developed too - April and Casey, even Karai. Winters is an interesting villain, I won't say more as I won't spoil the plot. My only complaint is that we didn't really see more battles with the 13 monsters... but then this movie wasn't action-centered.
The CGI is really good - the backgrounds especially, sometimes you forget they are CGI. The characters are done much like in the style of the Incredibles, bit hard to get used to but it works well.
I hope there'll be a sequel, as even Karai hints at the end the Turtles will see the return of some familiar faces...
