The Kinvara is the light one. At roughly 206 g, with a 28 mm heel and a 4 mm drop, it sits closer to the road than almost anything else Saucony sells, and there is no plate in it. Speed here comes from your own turnover, not from a lever under your foot.
It suits you if you want to feel the ground on faster days, or if you like a low drop and a shoe that stays out of the way. Repeats, tempo runs and shorter races are where it makes sense.
It is not a long-run shoe and it is not a first pair. There is little foam between you and the pavement, so a heavy week in it will find your calves before it finds anything else.