That clip was a fine example of the Lee Strossberg school of method acting. Tops Adler or Jeff Corey's style any day. Of course this would be tongue in cheek.
In my view, DeNeros best work was Cape Fear, A Bronx Tale, GodFather II and GoodFella's. Casino being right up there. Every actor uses their own tricks, but Pacino rely's way too much on his. At times, Pacono looks like he's acting over the top. DeNiro does not, making scenes look like he's reacting rather than acting. Even a much younger DeNero in Mean Streets shows that potential. Funny about him playing mostly Italian-Americans when he's three quarters Irish.