How bad is it? It's an intentionally cheesy monster flick.
Should you see it? All giant spider films have their moments, this one included.
Every decade or so, there's a giant spider movie and they run the full spectrum in quality. This one is squarely a B-movie in mentality, follows all the predicted plot paths and still manages to poke fun at some of the cliches of the genre. A meteor shower interrupts a DNA experiment aboard a NASA shuttle, which leads to people becoming the breeding grounds for spiders, which get bigger as the film goes on and which quickly spread beyond the confines of reality. This is watchable, not terrible, a "see it and forget it" kind of film.