In contemporary America, and presumably elsewhere, there are a lot of subcultures that have an expectation that whatever ostensibly weird thing it is they're into is honest, real, and completely harmless, if not virtuous. The corollary is that you should be fine with it, and even if there are some things about it that don't make a lot of sense, you should politely nod, say something like "that's very interesting," and not try to poke holes in it. Which this movie flatly tells you, so there's not much doubt about this being its main message. Because it revolves around this, your enjoyment of it is likely to depend on where you stand on accepting such things, like that there are real-life "vampires" who (from their POV) need to drink blood. (This is a 100% real thing, in the real world; they ain't making it up.) Enthusiasts of unconventional subcultures are likely to enjoy the message and representation, while the more conservative among us will probably be turned off by it.
Coming from what I feel like is a middle ground on this, it's a middling movie. It has a real intention to be a "rom-com," so it follows a familiar formula, while trying to use that familiarity to comment on the message at hand. It's somewhat successful there, and the plot has above-average smarts, relative to the world of rom-comery. It can be somewhat sweet and amusing, but the comedy is very broad, often crossing into corniness, and still, as someone who doesn't completely buy into the message, it isn't funny enough to let me wholly sympathize with plucky vampires trying to get away with tax evasion.
