not great - but it could have been

It could have been pretty decent - the actors did a fairly decent job, except for a few moments when it went too far for the lols and failed.
The main issue is the inconsistency. There are 5 types of vampires - or so they say in this film. At the very least, it's one way in which they try to explain away the inconsistency which is present throughout the whole film.
Killing vamps is done very oddly - some die from one bullet, others do not - one vamp died just by falling down after getting legs shot off - lol Basically, when convenient, vamps turn into one shot one kill creatures, and in other instances they turn into bullet sponges and shrug it off.
Same applies to humans turning - Snoop didn't turn vamp after getting bitten, while another dude did turn. BTW, since when did familiars turn on their master vamps in an instant?

Basically, when they apply logic and rules in one case and ignore the established rules the next moment, it tells you that the only logic present in this film is that of convenience. If they applies rules consistently throughout the whole film, and if did not go overboard with their attempts to get haha's from the viewers, this film could have been really good.