In terms of showing off a DC universe, this episode felt like it was could have been made by Nolan. The references made me smile even though a lot of them were just teases. The acting was great and the episode was shot and editted well. However in terms of a finale for the show I just watched through and enjoyed, I was expecting more. The fact that technically there was only a minute or two of actual "finale" in the episode annoyed me a lot.
TLDR Great as a stand alone piece, not so great as finale to the show
Also watch till the credits end for a fun teaser