*FYI my reviews are usually grumpy*
Eh, it was okay. Not having Branagh to temper the Asgardian stuff was a loss, just came off as generic sci-fi/fantasy. Eccleston wasted as bad guy but he got a good paycheck I'm sure (though stuff 'im for skipping Dr. Who 50th anniversary, the jerk). Dark World is an example of what I DON'T want Marvel movies to become: generic Outer-spacey fx-ridden noise.
Hopefully they realized this because the ending promised more Earth and less Asgard. The few minutes of Thor on earth were easily the funniest and best scenes in the movie with the exception of a great 'stars and stripes' cameo courtesy of Loki. The fish out of water aspect of Thor is what makes the character work. When he's at home he's just another demi-god and overshadowed by Loki (Hiddleston does the heightened performance necessary better than Hemsworth).
That said, there IS a reason to watch the Blu-Ray (and I mean the disc, not streaming or on cable) and that is for the EXCELLENT short film ALL HAIL THE KING starring the awesome Sir Ben as 'Trevor' in prison with an interesting twist to the Mandarin storyline. It is f*cking hilarious.