Insidious (2010)

"When proud parents take possession of an old house, an accident results in one of their sons falling into a coma. The tragedy doesn't stop there when they are beset by vengeful spirits from another realm in this new chiller by the director and writer of Saw and by the producers of Paranormal Activity."

I've read that "Insidious" is just a reworking of "Poltergeist" (1982) with Darth Maul as the bad guy. Has anyone seen it yet to confirm this?

The story also sounds a lot like like "They Wait" (2007) to me especially the part about the kid being in a coma.

Having also read that it's supposed to be really scary but with a big chunk of comic relief added by the paranormal investigators, should I be worried that this is more of a comedy than a real horror movie?

I'm probably not going to see "Insidious" at the cinema anyway because yet another PG-13 horror doesn't interest me in the slightest but I'd like to read your thoughts on this movie before I make up my mind.

If you've written a review of "Insidious", please leave a link to it in the comments below.