I was kind of lukewarm on it. Benoist is great as Kara and the "super" aspect of it is really well-realized (seriously, best TV superhero VFX ever), but there was definitely something missing. It's easiest to compare this Supergirl pilot with the Flash pilot, but where the Flash really worked, I think Supergirl kind of fell on its face. It's the personal/family angle of it all. There's no true equivalent of the Barry/Joe relationship, or even a decent Iris. Hell, Smallville's pilot established multiple different relationships that worked; pretty much none work in Supergirl. There's four different familial characters in Supergirl, two of whom don't talk, one who has only one or two lines, and a fourth who's practically an antagonist and not very enjoyable to watch anyway. Even Kara's "friends" at her workplace are more weird than friendly.
It is a pilot, of course, and it's pretty crammed with plot, but still. That human element is why The Flash works, it's why Lois & Clark worked, and it's why Smallville worked for a few years at the beginning. Supergirl needs that too.