Just got back from seeing the movie and I have to say that not only am I pleased, I am *astonished*.
Star Trek XI was, frankly, not very good as far as I'm concerned. It has a nonsensical plot and characters who served little purpose aside from spouting familiar quotes. Not to mention that I felt like it didn't stand on its own legs with so much 24th century stuff in the movie (who were poor representations of Romulans to begin with).
But STID? I really had a great time, and I was watching the movie with a really scathing eye this time around. Unlike Wrath of Khan, which is a moronic, nonsensical movie with a short-sighted idiot as a villain, I took STID's Khan seriously and he actually acted intelligent and dangerous unlike Montalban's. The characters all had more depth, we got to see a little more of the Star Trek world, both on and off Earth, and there wasn't this dull section in the middle.
I didn't like the magical blood subplot, but at least they set that up early in the movie so it didn't seem like they pulled it out of their ass. I also felt there were a few too many shots of the Enterprise crew dying and felt a little uncomfortable after a while and felt like "Yeah, I get it...", and Spock Prime's little scene was basically pointless. More cracks in the armor may show up on repeat viewings but I still dig the movie despite these gripes.
It was a lot of fun, it was much more TOS-centric, and everything from the plot, to the characters, to the pacing (and even the scoring) was better. Yes, they did reuse a lot of stuff from one of the Star Trek movies, but it was a terrible Star Trek movie and they made those elements work here where they didn't before. Cumberbatch gets a thumbs up from me, as does the rest of the movie.