Granted, I have only played for 20 minutes.  So far, I really like it.  I am a huge fan of the franchise, so I can forgive a lot. 

The reviews, except the IGN one, have been average.  From what I have read, the framerate seems to be an issue. 
Some say the combat is "weak" but I feel this as been the case for all of the Silent Hill games.

I think it would be interesting to gather some opinions on this game.  It would be nice to avoid spoilers if possible.

I have played most of the Silent Hill games, SH2 being my favourite, followed closely by SH3.  I enjoyed Shattered Memories on the Wii but I could not bring myself to finish The Room or Homecoming.  I have just downloaded the first one on my PS3 and I will buy Origins soon.  So I have high hopes for Downpour.  I thought the opening sequence was well done (showers) and I want to advance the story to know more.  I find the graphics amazing.  I can't wait to get inside Silent Hill.

Massive night of playing coming up.  Please share your opinions.

Thanks!

So, I have played much, much more. This game is creepy as hell. The Silent Hill vibe is really present and the music really helps the mood. The game is really creative and it has excellent atmosphere. One of the level is the best I have seen in a horror game, including all of the previous Silent Hill games.

Please, don't base your judgment on the IGN review. They really went out of their way to destroy it. As a fan of the Silent Hill games, it's one of the best in my opinion.

I don't know if there are any references to previous Silent Hill games, but it seems to be a standalone much like Homecoming.

But with the Silent Hill HD Collection coming out, you're really better off getting that. SH2 is an all time classic, and SH3 isn't much worse. Plus it's cheaper than Downpour.

In my opinion, it is a fantastic survival horror game in it's own right.  You will definitly get the "feel" of the previous Silent Hill games when you'll play it.  So, in my opinion, you should not let it pass if you like these kind of games.  Also, I suggest you look into the Silent Hill collection coming next week.  You get Silent Hill 2 and 3 in their remastered form.  You must do yourself a favor and try them out.  I hope this helps.

I recently finished Silent Hill Downpour and although it's far from great as a whole, the 2nd act, exploring Silent Hill, was totally worth it.

The negatives first.
Dated graphics with poor performance. There were times in the beginning where I thought the game had crashed but it just likes to lock up for several seconds at a time. Textures are continually being updated around the edges which pretty much destroys the whole effect of things moving at the edge of the screen. The frame rate stutters a lot, especially when running which can cause the camera to turn wildly as it applies your last input over the missed frames. The first act is pretty linear and not much fun imo. The last act is pretty average too. The other world chase sections are more frustrating then scary as you keep running around in circles trying to find the next trigger point.

Yet the middle part, from the moment you arrive in Silent Hill proper until you leave is some of the best game design in a while. The balance between combat, exploration, puzzles, side quests and story progression is perfect. Side quests are all vastly different with a few really good ones. (movie theater, turn back time)
The centennial building and monastery are great places to explore with plenty of interesting pieces of information to find. The theater quest in the monastery is my favorite. The town itself feels real and has plenty of places to discover. Combat is satisfying enough, not great, but that's not what draws me to a SH game anyway.

A game of two halves. It would have been nice if the north east section of the map was available too instead of the final act. Maybe a few more buildings to explore and some more claustrophobic underground exploration.
And it would have been awesome if there was a 2nd campaign where you can play through the whole game as the cop instead with different objectives.

I rate it 7/10 for the game as a whole. 9 for the 2nd act, 6 for the rest, 5 for performance.

Overall it was a great game. Sure it has it its issues. The combat was horrible. The graphics werent up to date.

But it was a step in the right direction. Great atmosphere, great story, great animations and a long game.

I give it an 8.