Decent? Maybe... but best movie of the summer? Not even close. In summary, this was a fun popcorn movie, but not even close to being the best movie of the Summer. In my opinion, it was better than Thor, not as good as Captain America.
Harrison Ford in recent years has given up. He doesn't even look like he enjoys being in movies anymore. He's crotchety and devoid of any emotion beyond irritation. His only saving grace is that he only takes roles in which he is crotchety and irritated throughout the movie. He just seems to suck the energy out of every scene in which he appears.
The female lead is a throwaway character. The whole native american thing was cheesy and ham-handed.
The plot holds together just enough to keep things going, but you really have to consciously avoid giving it too much thought.
Like Thor, this was a movie that ultimately fails to deliver completely on its potential. In both cases, I regret the money spent on tickets and would have preferred waiting for blu-ray.
So far, for me, the standout movies of the Summer so far are X-men First Class, Green Lantern and Harry Potter, although I have high hopes for Rise of the Planet of the Apes.