I saw it. I'd say it's a B, I enjoyed it, but have no urge to see it again anytime soon.
There are some points I wish the movie was more clear about
Like, what exactly was the legal standing between Elysium and Earth? In some cases it looks like Elysium is a sovereign separate nation (one of the charterers mentions having embassies down on Earth). In others, it seems like Elysium is ruling the world with only the rich having citizen status.
I'm guessing the movie chose to be vague on this point since it wanted to focus on more on the issue of access to health care.
One spoiler nitpick: