I think Norton did a great job as Bruce Banner in this movie. It is unfortunate that he was replaced (although I do think Mark Ruffalo did a fine job as Banner in The Avengers), although if the rumors of Norton being difficult when it came to making this film are true I can see why he was. Norton did a great job portraying the conflicted nature of Banner and the frustration and fear that the character feels. I also think he has fairly good chemistry with Liv Tyler, who played Betty Ross, which was necessary given the role her character played in the story. The movie does set up a possibility of a sequel, but obviously, Marvel has put higher stock in the Iron Man, Captain America, and Thor franchises (and the Avengers team-up movies). Whether a sequel to this movie ever gets made, and if so whether it continues the story started here remains to be seen.
I think the CGI Hulk is far better in this movie than it was in the Ang Lee version. I think it was one of the things that detracted from that version of the movie, but the technological advancements in CGI have come a long way, and while the Hulk does not look totally realistic, it looked a lot better. Ferrigno has gone on record saying he thinks that Hulk should be played by a real person, but given that the Hulk is supposed to be 9 feet tall, that is just not practical. If you notice in the film, while Ferrigno is substantially bigger than Norton, he is not that much taller. And they would have had to go back to the tricks used to film the series, like cutaways and filming Ferrigno (or some other actor) from below to make him look taller. A CGI Hulk just works better. Especially for the battle scenes. There is just really no way they could have done any of the battles (especially the end battle with Abomination) without the CGI.
The A/V quality of the Blu-Ray is outstanding. The special features consist of some behind-the-scenes material, making of documentaries, deleted scenes, and trailers. In all, if you are a fan of the Marvel series of movies, while this movie is not as strong as the first Iron Man or the Avengers movies, it is on par with most of the other MCU movies and is definitely worth the time to watch and adding to your physical media collection (if you have one).