I spent $18 for the IMAX ticket last night (including the $1 processing charge on Moviefone.com). And, I agree, it was worth the money. I could definitely nitpick a few things, but overall it was a fun ride. I grew up with the original and watched all the series. Voyager was the beginning of the end to me. I can understand why they did Enterprise, but they did it wrong in my opinion. I stopped after the first season sometime. I'm glad it had a rest. It needed it.
I didn't like all the changes, but the casting worked. Karl Urban as McCoy is given some great lines and delivers them perfectly. And the new Checkov actually sounds Russian (I think the kid is of Russian ancestry, but I don't know if he's a native speaker at all.).
The story is really good, despite a couple of detours I had trouble with. The effects are good but do not dominate the movie. Things keep moving without it feeling like an out of control roller coaster.
The highest compliment I can pay them is that they did what they had to do to establish their own version that can stand on its own.