It didn't suck! Well, there were times when sucking was involved, but this is a vampire movie after all. (That's as close as I'll probably ever get to making a pun, so write it down on your calendars.)
I had no previous contact with the tv show, and I think that's a good thing. I had no preconceptions about how it should be. The overarching theme of this movie is the same as Fatal Attraction. Be careful with whom you have casual sex. Your partner may not feel so casually about it, and that could come back to haunt you and everyone you love in the end.
I've seen the genre for this film described as Comedy/Scifi/Fantasy/Horror, and to that I would say, yes. It wasn't as campy as I was expecting. There were scary parts, but it didn't cross my threshold (which is very low).
I had a good time. Costumes were great. Johnny was fun. If I had to make one criticism, it would be that it almost seemed like a tv show pilot. They introduced several different threads, and I didn't feel like they spent enough time on them. You know the way they do for a tv pilot, and then over the course of a tv season they flesh the threads out. More than you would need for a squeal though the door's open for that too.
If I was ranking it I would say 3 1/2 out of 5 stars.