Mike,
Save you money. What a waste of a great story line. Avatar was a similarly cliched story, but was done so beautifully that I went to see it twice, and would see it again.
I enjoyed it until it got ridiculous (don't want to say if you are going to see it) and then started wishing I was watching MIB III! It had a good story going but lost it. The butterred popcorn was good!
I saw it and had mixed feelings afterward, but the more I thought about it, the more disappointed I became. It could have and should have been epic, right up there with Alien and Aliens, which my friends and I still quote to this day. So much about it didn't make sense, you've got to wonder if anyone asked for critical feedback about the script before they began filming.