I never minded vamps in Whedon's shows (and I have no big love for him) and I like them fine on SPN.

I think when it comes to guys chasing the female lead, it comes down to how it's handled. If it's for plot reasons--she has something they need or they want to use her to get to someone else--I'm a bit kinder. But in so many stories it seems like a dozen or so men fall head over heels in love with the main female lead and that just annoys me to no end.