The concept behind the series was pretty good, the execution of it though, was very bad.I tried watching a few episodes of it, but I could never get into it. I don't really get why, but something about the dialogue and the creatures just didn't capture me as much as Doctor Who.
But still, it wasn't truly, stupendously awful. That has to go to ITV's Demons, a bad Buffy ripoff with awful dialogue, awful effects, in fact let's just call it flat out awful. Thankfully it's not coming back as Philip Glenister watched it and realised the series is the very definition of fail and left it, preferrring to be Gene Hunt and thus putting an end to it.
Primeval, though, I enjoy a lot. It would be nice if the UK could start to do a fair bit of sci-fi again.