Wrong Turn series... any good?

[cuzzin]

I recently picked up the 6th installment on Blu-ray. I wasn't really even trying to buy it, I just wanted to see if Best Buy would sell it to me because, apparently, some people on here had issues trying to buy it in stores because the studio has issued a recall of the film. Now I have the sixth film without having seen any of the others, outside of the original with Eliza Dushku. So now I'm thinking about buying the first 5 films on Blu. How would you guys rank this series against other horror series, such as the Saw franchise? Is there a continuing, connected storyline that spans the series or is each film just a standalone movie?