How bad is it? It's okay for an unneeded sequel.
Should you see it? If you're bored and it's around.
I think this got terrible reviews because it has nothing to do with the previous films in the series, nor with the Stephen King story that started the series. It's a remake of "The Thing." People die in Antarctica, guys get sent to investigate, dead bodies reanimate, they discover something Satanic. The first half isn't bad, but it gets implausible - a guy goes outside shirtless... in Antarctica - and there's a tacked-on romance. Faith Ford is the biggest name in the cast.