Finished the series now, I thought it was decent enough that I'd watch another season. I am a bit of a sucker for some of this sort of fantasy stuff (in a very general sense), I was a fan of Buffy the Vampire slayer back in the day (well for the first few seasons at least), I've watched some of the Vampire Diaries episodes too (not exactly great but is easy to watch trash TV when bored), I really wanted to like the Shannara Chronicles but that show turned out to be complete guff. I really, really like Game of Thrones and Harry Potter, but then again who doesn't.
There are certainly a lot of influences from other contemporary films/TV shows - Sabrina has her version of Hogwarts to go to, while there isn't a Slitherin House per say there are the three sisters who don't like the fact she's a mudblood half-breed. There was almost a bit of a hunger games reference re: the episode with the "tributes" being drawn by lottery. There is potential I think for twilight style love triangle where she might go for the warlock dude at the academy over witch hunter descendent. There seems to be some Vampire Diaries influence too with regards to the old town setting and the various historical families and their links to the town, in the case of Vampire diaries historic Vampire hunters, in the case of Sabrina she's dating a descendent of a Witch hunter. Much like Buffy some of her pals have developed their own special skills. Though they managed to throw in the good old "magical negro" trope with Rosalind's wise old Grandmother and the "cunning" special sense she has, which of course Rosalind develops too.
Like the above poster I'd have liked to see some more comedy, especially given the casting of Lucy Davis and Michelle Gomez. I'd also have preferred to see some of the characters being a bit more flawed... for example she has this boyfriend who is seemingly every feminists' dream - he's rather anti-masculine, sits there obediently with her chums, he didn't shoot the deer etc... would have perhaps been more interesting to have him perhaps shoot the deer, be a bit more flawed, have a bit more conflict with her instead of simply having him do nothing wrong and just have Sabrina make mistakes.