Ok, this is what I thought of it. There are serious spoilers in this post, so I colored them the same as the background. If you are ok with reading them, just highlight below.
1) Data dies. I am so NOT OK WITH THAT!
2) WTF is up with him downloading his memory into B-4? I mean, how Wrath of Khan can you get..."remember..." Give me a friggin break.
3) They might as well have left Troy, Crusher, Worf and Reiker out of the movie. I would have prefered that to having them have no usefulness.
4) WHERE THE FUCK DID THE CATWALK COME FROM??? I never once saw a catwalk above a bottomless pit on the Enterprise before...but now there is one? What is this "Galaxy Quest"?
5) The plot was loose, and could have been SO MUCH BETTER!