$15? Wow! Grab it! Grab it now!
It's a good old fashioned epic. This is no Gladiator, but it's a big story, massive battles, looks gorgeous (on blu-ray? You'll wet yourself, surely), and it's got Eva Green in it. Points against, well, a lot simply don't like Orlando Bloom. I'm less inclined to trash him, but he is weak. He's supported by some big names though and I kind of think the story works because he's a bit wet, if that makes any sense. Also some plot points feel like they were left over from Gladiator, but the good outweighs the bad by some margin.
Look at it another way, I saw King Arthur the other day and in direct comparison, Kingdom of Heaven is superb!