All the commands in Unix/Linux are a bit weird 'cos they were trying to differentiate themselves from existing operating systems. I remember being told long ago that you always have to think of the second-most-obvious possible word for what you want to do. So there are man (manual) pages instead of help pages, that sort of thing.
The point being that that's exactly what happens in this show, and it's so hideously obvious it gets in the way. They don't slay vampires, they "smite" "entities" ("smite is such an intrinsically daft word). What makes it particularly bad is that Luke the Entity Smiter goes along with it almost straight away, instead of pointing out to !Giles (who is called Rupert and whose surname starts with a G, which doesn't help with the feeling that someone's run a search-and-replace on one of those male-vampire-slayer fanfics) how silly it is.
Other than that, it turns out Philip Glenister is great even when he's doing utter tosh and using a dodgy American accent that occasionally slips. Luke spent a pleasing amount of time with his shirt off. I was very worried that Ruby (named so they could use the Kaiser Chiefs song, y/y?) was going to end up stuffed in a fridge to give Luke Motivation On His Heroic Journey, but she didn't so I was glad. If the show ever gets a serious fandom I predict classism wank about her, because there are various disconnects between what the show is showing and telling about her background. Mina Harker is out of LXG, but so was the finale of the most recent Who.
The bad guy being a pedant who liked puns was lulsy, but possibly not menacing enough for your very first episode, hmm. Also, I'm getting a bit sick of shows that are conscious of the shippy elements of fandom and deliberately tease them. Like with the entity-smiting it's just distracting.
I will probably watch it again.