The showing I went to yesterday wasn't particularly full. I wouldn't even say that the theater was half packed, but it was 5:00 on a Saturday, and around here, nothing really "happens" until 7 or 8, so on a Saturday you can still find places to park/get a table at a restaurant right away/etc. if you're relatively early.
My friend said she LOVED it. It was really hard not to say anything when I knew what was coming at every turn, but I like second viewings of movies I love because it gives me a chance to look for the subtleties that I wasn't able to catch the first time.
Sharon thought Ckekov was adorable and thought it was eerie how at times he sounded just like Walter Koenig, and not just because of the accent.
I don't remember if it was in this thread or another, but someone here had asked why Chekov was giving the mission report instead of the captain. The conclusion Sharon and I came to: it just wouldn't have been as funny if the captain said "Wulcan" a lot.
Still deciding on what my favorite line is.
McCoy: "Green-blooded hobgoblin..."
Kirk: "STHOP IT!"
McCoy, and later Kirk: "I might throw up on you."
Spock: "I have no comment on the matter."
And Scotty asking if they still have sandwiches in the future!

ETA: This time around, I also thought Sulu was even more awesome.