Downpour's greatest strength is the ability to explore Silent Hill to the point of uncovering an impressive number of side quests that are probably more compelling than the redemptive grieving-father-cum-vengeful-prisoner story.

The design of the town is much more fully realised than Homecoming, allowing you to enter various interesting new locations, most notably, for me, a cinema showing a mysterious film you can walk into (pretty weird).
The game still has a number of lows, most notably the silly crazy ghost train adventure in the ol' mines. Some of the supporting characters also feel incredibly plain, such as postman guy.
Subtlety is long gone by this point, and unfortunately the one thing this game is not is scary. But at least it's also not Homecoming!